


Unexpected Attraction

by eikuuhyo



Category: Undertale (Video Game)
Genre: BDSM, Body Worship, Bondage, Bukkake, Cunnilingus, Deep throat, Dirty Talk, Double Penetration, Exhibitionism, F/M, Fingering, Foursome, Master/Pet, Nipple Play, Orgasm Delay/Denial, Petplay, Skeleton dick, Spoilers, Tentacles, Threesome, telephone sex
Language: English
Status: In-Progress
Published: 2015-10-29
Updated: 2016-01-04
Packaged: 2018-04-28 18:14:47
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 19
Words: 37,445
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5100725
Author URL: https://archiveofourown.org/users/eikuuhyo/pseuds/eikuuhyo
Summary: <blockquote class="userstuff">
              <p>You never stood out amongst the crowd and never had any confidence in yourself. Sans, however, saw beauty in you.</p><p>Story takes place with a female reader after the True Pacifist ending. Refer to the notes for more details.</p>
            </blockquote>





	1. Attraction

**Author's Note:**

> This story revolves around a female, of-age Reader in the world after the True Pacifist run, so spoilers beware. You now live with Toriel and are helping teach at the school where Toriel works. At first, it was going to be just a collection of drabbles, but the whole setup of the scene got out of hand and now this is going to be a multi-chapter smut fic of Sans/Reader!

The life you've lived until now had been filled with much mockery. Before you had fallen into the monster world that fated day, you were no one in particular. As a child, kids made fun of you at school for being short and boyish. As a high school student, the others laughed at you for still being short and having almost no curves at all. All the other girls around you had blossomed into beautiful women, while you were left in a perpetual state of child-like looks... That was the inferiority complex you held deep within you.

Even when you fell to the monster world, you still felt inadequate. Yes, the residents of the underworld were all monsters of various shapes and sizes, yet the mature ones were still beautiful in your eyes. Some had curves, others had muscles... But then, there was you. A small girl with barely any showing of femininity.

Your haircut has been the same since childhood, though you had grown out your bangs a little more to cover your eyes since it gave you a false sense of security that if you couldn't see other people, they wouldn't take notice of you. Your hands, arms, legs, and even your body was bony no matter how much you exercised or ate... and eventually you had given up on even trying to try and make yourself more presentable.

There was a time in which you wanted to change, so that you could gain the attention of a certain skeleton monster in particular: the delightful pun master of the underworld, Sans. He didn't seem to jump to conclusions or mock you for your appearance. You were shorter than him, for god's sake, but he never made any jokes about it. He was one of the many monsters you met that made you feel better about yourself. And that was why you wanted to change, so that Sans would notice you.

Still, your resolve did not last long as you saw after the final battle against Asriel that there was a general attraction from Sans directed towards Toriel. She was a wonderful monster that took you in as her own in the beginning, and even accepted you as her child when you and all monsters returned above ground into the human world. You could understand why Sans would be attracted to her, and thus, your short-lived crush came to an end.

...Or so you thought, until now, as your body and mind was frozen in place at seeing Sans taking one of your hands and placing what could be taken as a kiss on your bony fingers, his one eye blazing a tinge of blue and yellow from desire.

 

* * *

 

The day had started out like every other one until now. You went to school with Toriel to teach the monster kids about the basics of the human world, broke for lunch, and then came home early to change into more comfortable clothes—mainly a tank top and shorts since it was getting rather hot because of the early summer weather—to prep dinner. The skeleton brothers always came by every other day to eat dinner with you and Toriel, and today was one of those days. After tonight's menu of spaghetti and meat balls was prepped and simmering on the stove, you had heard a knock at the door. A quick check at the door showed that Sans was here early.

You happily opened the door and welcomed him into the house, though Papyrus was nowhere to be seen. You were about to ask Sans if his brother was running late when you noticed that he was acting... somewhat odd. From your perspective, it seemed as if Sans was frozen where he stood. His expression was still stuck on his usual smile, but only his eyes seemed to be moving slowly up and down. That's when you remembered your current physical state.

Of all the people that had to see, Sans—the one whom you still can't give up your crush on—had seen you in the most plain of outfits. Not only were you showing off more skin than ever, it suddenly hit you that your thin, pale arms and legs were all showing. You had given a nervous laugh and grabbed a nearby jacket, throwing it on while trying to make a joke about how you didn't want to get tomato stains all over your nice clothes while you were cooking... to which it had seemed Sans' expression had turned into a small frown. There was a small pang in your heart seeing his demeanor change, only if it had lasted for a second of so, for in your mind, you assumed that your physical sight has disappointed him. Still, you hid that pain and pleasantly invited him inside.

After some time spent chatting with the now-distracted-seeming skeleton, Sans had suddenly fallen silent. He seemed to be pondering something, which concerned you for you've never seen him be like this, until he stood up and quickly took your hand. The touch surprised you, but you didn't have any time to voice it as Sans tugged you off the sofa and began leading you upstairs... to your room.

You let him gently push you in as he followed and closed the door. Confused as to what Sans was doing, you were about to ask what's wrong, when he just quietly shushed you and had you sit down on your bed. He then silently knelt on the ground before you and took your right hand to gently press his teeth against them—which could've been taken for a kiss had he lips, and that was where you were now.

 

* * *

 

Just feeling his bony fingers hold yours, his teeth grazing the back of your hand, and that burning look in his eyes made your heart begin pounding in your ears. You have no idea what's going on here, only that Sans is acting strange. Strange, and utterly desirable in your eyes.

"S-Sans...? Um... What's going on...?" you manage to mutter out, though the last word barely comes out as a small squeak.

Sans lowers your hand that he's holding from his face, all then while maintaining eye contact with you. He gives a small sigh before pulling himself closer to you. "...Kiddo, tell me if I'm overstepping my bounds."

"U-Um... No...? Actually, I-I just want to know what's going on...?"

"...You," Sans whispers while rubbing his skeletal fingers over your thin ones. "For the love of god, tell me if I'm reading the signs wrong."

"S-Signs...?" you mumble back, the heat in your cheeks rising even further. He couldn't possibly mean what you hope he means—

"...You have no idea what you do to me. Your personality. Your physique. The way you look at me. The way you treat me," he pauses there for a moment, trying to figure out how to speak his mind. "Kiddo... please tell me. Do you like me?"

His words are barely a whisper. There is a sense of desperation, of hope in his voice, that you can tell that what he is saying is genuine.

Your face is practically on fire as blood rushes up even more, your eyes darting around the room, but not being able to avoid the burning look in Sans' eyes. It takes another minute—it felt like eternity to you—before you finally muster up the courage and squeak a small, "Yes," to him. Had there been a hole somewhere in your room, you would've most definitely jumped in and hid yourself in it for the shear embarrassment you were feeling.

Then again, your unease is cut short as you are quickly grabbed and tackled into a hug onto your bed. A high pitched eep leaves your mouth at the unexpected embrace as you feel Sans squeeze your body.

"Dear god, you have no idea how long I wanted to ask you that...!"

"U-U-Um... Wh-What do you mean...?"

Sans is practically straddling you as he let's go and gives a bright smile. The small, blue blush on his face is utterly adorable.

"I've liked you since I met you, kiddo. There's a reason why I kept showing up, talking to ya and stuff, you know?"

"I-I just thought you were being nice... I mean, y-you are nice to everyone, after all..."

"Nice is one thing. I kept throwing bone after bone at you, trying to see if the gazes you were directing at me were in that way or not."

"You did...?"

This time, Sans rolls his eyes. "The first time we met. Each time before you'd run into Papyrus. That place with the reindeer. Etc, etc... I even showed up before you faced Asgore. I only did it for you, kid. I didn't want anything happening to you."

That does trigger some memories. You remember every time you felt like you were about to give up or couldn't keep going, Sans always showed his face to offer you some words of wisdom. Had it not been for him, you doubt you would've been able to finish your journey. However, there was still one question that remained.

"B-But... I thought you liked Toriel...?" you mumble out, since you now have the courage to speak that single, greatest doubt in your mind.

Sans looks genuinely perplexed for an instant before giving a good laugh. "Y-You thought I liked Toriel that way!? Hahahaha, ohhh you sure know how to pick at my bones... Hahaha... Nah, she's a good friend to me, but nothing more, nothing less... Not like you." Once again in a flash, Sans' playful demeanor disappears and he's back to looking at you with that heated gaze of his. One of his eyes has a mysterious yellowish blue tint to it, and you can't help but shiver under its light.

Your mind is overwhelmed at the crush-of-your-life's love confession for you. Part of you is jumping up and down in utter joy, yet there is also the insecure part of you that is rearing its head. You can't even begin to comprehend what Sans sees in you, let alone look at you with such... desire.

As if sensing your shift in emotions, Sans cups your cheek with one hand. "...What's wrong?"

"I-It's just that... you know... I-I don't really know what you see in me... I'm not pretty, I'm probably closest to a skeleton than any other human being, I'm short, and, and —"

"Kiddo, you're _perfect_ ," Sans says, cutting your rant off. His face comes extremely close to yours as he practically drapes his body over you. "You're more beautiful than any monster or human I've ever seen. You have no idea, how much you make me want to bone you."

You can't help but give a small laugh at that sexual joke. However, Sans seems to be upset that you aren't taking his words seriously and his smirk turns to one that seems more... predatory?

"Well... if you don't believe my words, I could always show you what I mean..." he practically murmurs into your ear, making your face blush brighter. Sans sits up while still straddling your hips and brings one hand to the edge of your tank top. Bony fingers slowly snake up while tugging on the light fabric to expose your pale belly.

Your heart is pounding for the umpteenth time today as your mouth goes dry instantaneously. You should be trying to stop him, yet you can't help but wonder exactly what Sans meant by "show you" what he means. Just as the edge of your shirt is about to be lifted past your lower rib cage and reach the bottom of your breasts—

"Hello dear, I'm home! I ran into Papyrus on the way home, so we've come back together!"

The sound of the front door opening and Toriel's cheerful voice echoing up from downstairs snaps both you and Sans out of the sensual atmosphere that had built up. You quickly pull down your shirt and call back to Toriel that you will be down in a moment. Sans has also stepped off your bed with a hint of disappointment in his smile.

There is a small amount of relief in your mind at Toriel's return, since there was no knowing how far Sans would've gone at the rate things were going. You take in a deep breath and are about to reach for the door, when Sans takes a hold of your hand again. He quickly pulls you towards him as he whispers, "...Guess I'll have to show you later, hm? Don't worry, I'll make sure to assure you that I'm not joking when I say that you're beautiful. I'll spend minutes... hours... the entire night, if needed. Be prepared to have another skeleton in you other than your own." He then lets you go and nonchalantly leaves your room.

It takes more than a few seconds for your brain to understand what Sans had said to you, and when it finally does register, you unconsciously grip your chest at his last words. Today was dinner with the skeleton brothers, after all. And when they had dinner, the brothers usually stayed over for the night in the guest rooms so that they would not have to make the long trek back home in the darkness. Which meant... only one thing.

Sans would not go back on his word. Whatever it was that almost happened a few moments ago would be happening.

This was going to be a night to remember, and after all the months that had passed since emerging from the monster underground world, you were filled with determination to not let your pessimism win for once.


	2. Praise

**Summary for the Chapter:**

> Thank you so much for all the kind comments on the first chapter...! I can't even express how much it makes me happy to hear that people are enjoying my writing. This chapter was supposed to cover the full night, but Sans got out of hand with the body praising and so the smut will continue in the next chapter.
> 
> The same cautions apply as before. Please enjoy!

Dinner over at the Toriel family's house went smoothly without any hitches. Toriel, you, and the skeleton brothers had a nice conversation over the events that had transpired today as the four of you enjoyed the fresh cooked spaghetti and meat balls. You particularly enjoyed Papyrus' stories of his endeavors in the human world. He had taken up a hobby of photography as he traveled around on his amazing looking car. Some after-dinner butterscotch pie and tea was served before everyone called it a night. Sans helped tuck his sleepy brother into bed in the guest room while Toriel took a shower and headed off to bed as well.

You were the last one left downstairs at that point. Dishes were cleaned up and drying on the rack. Leftovers were wrapped up and put into the refrigerator as everyone's lunches for tomorrow. You made one last sweep around the living room before making sure that the front door was locked, flipping off all the lights as you headed upstairs to freshen up... and then head to bed.

 

* * *

 

Your heart is practically pounding a mile a minute as you stand before your bedroom door. If you are to believe Sans' words from earlier—which you do—then there is no doubt that the skeleton is waiting for you in there. You've never been this nervous ever in your life. Hell, you were a stumbling wreck even taking a shower a few minutes ago, let alone try and get your pajamas on. It had taken you three attempts to button up your pajamas, since every time you buttoned up, you'd realize that they were one off from the correct spaces.

But here you were now. The house is utterly quiet, save for your nervous breathing and the strong gust of wind you hear outside. It takes all your courage to eventually grip the door handle and slip into your dark bedroom. The door closes behind you and when you hesitantly move your eyes up from the floor, you find Sans casually hanging out on your bed, the moonlight shining in from the window casting a white glow about him. He's got his usual smile on his face—though it seems more excited and wider than normal, to which you return an anxious one. A few moments pass as you shuffle your feet on the ground, not knowing what to do next.

Sensing your nervousness, Sans gives a small chuckle and beckons you over. He watches your every move as you walk across your small room, though when you get within arms reach from him, you are suddenly swept up into his arms in a tight squeeze. Your body tenses for a moment at the intimate embrace, but you quickly melt into the hug.

"You were taking so much time to come back that I thought you weren't coming," Sans mutters with a sigh of content as he holds you. "I was starting to wonder if the bone I had thrown at you was too big."

A small giggle leaves your throat as you respond back with a small, "Nothing you could throw at me could to be too big, Sans." However, realizing that what you said could be taken in a sexual way, you sputter out, "I-I-I didn't mean it in that w-way! U-Um, I-I just... Nnh..." You know that your face is bright red again, making you want to just keep burying your face in the skeleton's jacket and not look up.

Sans however, seems to have other plans. He gave an obviously interested sounding, "Oh?" while he pulls away and gently pushes you onto the bed so you're sitting on its edge. "Well... if that's what you want, I'd be happy to oblige... but that can wait." The giddy smile on Sans' expression changes into that same, predatory smirk from earlier. "There's more important things to do first, after all."

"M-More important things...?"

Only a nod is returned at your question. Sans kneels down like he did only a few hours ago while keeping eye contact with you the entire time. "...Tell me if I'm going to far and I stop. No hard feelings," he practically purrs. "Still, I'm going to convince you that you're a goddess in my eyes. Just make sure to be quiet. Don't want to wake anyone up, right?"

You are the one to return a nod this time. All you can do is tremble in anticipation while Sans brings both hands up and tugs on your pajama pants. You keep your hands tight in fists to both sides of your leg as you watch him slowly pull them off. The only relief you have is that your pajama shirt is long enough to cover past your panties and a little over your thighs—your pasty white, thin, bony thighs.

"...Damn," you hear Sans say in a slightly breathy manner. You're unsure as to what he means by that, though such thoughts are cut off when Sans takes one of your bare feet into his hand. A small gasp leaves your mouth at the feeling of teeth brushing against the top of your foot. "Humans sure are weird if they made you believe that you aren't perfect..." whispers the skeleton as he continues to graze his teeth from the tip of your feet and up your calf. He leaves light bite marks as he works up your leg, pausing now and then to run his bony fingers against your skin. "Obviously, I'm a skeleton. I've got no skin... but seeing yours makes me wish I had some. It's so silky smooth and warm."

Sans trails up to your knee at an agonizingly slow pace. By the time he's moved close enough to wedge his body between your legs, your breath is ragged and you're gripping the sheets on your bed like a vice, lest you lose all control and begin touching yourself. You had masturbated to such a scene in your mind before, but what you imagined was nothing in comparison to what Sans is doing to you now. This was barely foreplay, yet you could already feel your nether regions becoming hot and moist.

After Sans leaves a small kiss on your bony and bruised knee from playing with the monster children at school today, he stops and looks up at you. His smirk widens as if he's come up with a good idea. You watch curiously as the skeleton closes his eyes for a moment, and the next when he opens them, his left eye is blazing a cool blue with a hint of yellow, lighting up the room a bit.

"Don't think I've ever shown you this trick before..." Sans says as his eye leaves a trail of light when he moves his head. "But this bonehead's done some research too, you know? I want to make you feel good... And I know how."

The glow in his eye becomes a degree stronger before Sans opens his jaw and you gasp at what you see. A blue, phantasmal tongue snakes out and you can't help but bat your eyes in surprise. One more smirk is directed at you before Sans is back on your leg. Sans' magical tongue feels wet and warm as it slides up your leg, and you bite back a whimper as it brushes against the sensitive areas on your inner thigh.

"C'mon, kiddo... You know what I want to do next. Lift up your shirt for me."

Your cheeks heat up at his words. Of course you hesitate for a second, but your resolve crumbles as you feel Sans' other hand palm your exposed buttocks to knead it. Slowly, you grab hold of the bottom of your pajama shirt and lift it up with trembling fingers. You can practically feel Sans staring right at your crotch covered with plain black panties. Embarrassment hits your even harder when you hear him exhale hotly and mutter, "I've barely done anything and you're already wet? Guess you really do want me to bone you."

Had this been any other time, you would've voiced your opinion about the vulgar phrasing. The only reason why you don't is because soon after Sans had said those words, he had snaked his tongue up and began lapping at your pussy over the cloth. "S-Sans...! Ahh...!" the moans you can't hold back any longer fall out. If you two were the only ones home at the moment, you surely would've cried out his name just over that sensation alone. The thick tongue continues to lave up and down your crotch, pausing for a moment here and there to see where you react the strongest to. You clasp your hands over your mouth to drown out your whimpers, but it's hard to concentrate when the crush of your life is seated between your legs and showering you in pleasures you've never known.

After a few more licks over the now wet panties, partially from Sans' tongue and partially from you dripping wet from pleasure, Sans suddenly stands up, causing you to give a small yelp and fall backwards onto your mattress. You feel a burst of warmth envelop your body when you see a blue aura push you up further and fully onto the bed—perhaps this is his magic too?—and Sans climbs up as well. Skeletal fingers grab the edges of your panties and hastily pulls them off. As soon as the cloth covering your nether region is tossed off to the side, Sans immediately goes down on you, making your back arch off the bed in ecstasy.

You see a burst of stars while you keep clasping your hands over your mouth since you'd be moaning loudly otherwise. Your mind is a whirlwind of pleasure and panic while Sans hungrily eats you out, the thick tongue caressing each side of your pussy's folds. Each time your body jolts, the more the skeleton between your legs learns what you enjoy. Seeing you react most strongly to pressure applied to your throbbing clitoris, the tongue begins to focus mainly on that area. The tip would flick the sensitive nub from time before it press its entire length onto it, every move driving you closer and closer to orgasm.

The instant the thick tongue manages to snake into your tight entrance, your climax hit you sooner than you expect. Tears well up in your eyes as the ecstasy becomes too much for you to handle and your body trembles. You can feel your pussy clamp down hard on Sans' ghostly tongue as your pleasure peaks and you cry out the skeleton's name in completion.

"...Fuck, you're beautiful and delicious," Sans growls as he slips his tongue out of you and towers over you. He snaps his fingers hastily as you see blue again. Your pajama shirt is unbuttoned instantly with his magic, Sans finishing the job by opening it up to get a good view of your naked body. Under normal circumstances, perhaps you would've blushed or been conscious of Sans seeing your bare body, but you could've cared less after seeing the look of awe in his eyes.

"You said that you weren't pretty and closer to a skeleton than a human..." A kiss is placed on your stomach. "But god, you're utterly hot in my eyes...!" Another kiss to your protruding rib cage. "I could worship your body all night, and it wouldn't be enough." Another kiss on your sternum, and one more to your collar bone. With one last kiss to your neck and a hot breath left behind, Sans sits up and straddles your hips.

Though you're panting again from the praise Sans is giving you, your mind has finally gotten over the haze of the first orgasm and you look up to him. His one eye is blazing even stronger in the darkness as the moonlight behind him casts his expression in a dark shadow. The blue light seems to also be coming from his own crotch area, to which you wonder what's going on. You keep watching Sans as he undoes his pants and pulls them down to expose... a ghostly dick? Seeing your eyes go wide and mouth gape open, Sans snickers.

"Hey, I told you that you were gonna get another skeleton in you tonight. You can't even imagine how long I've wanted to bone you for."

"...H-How long... if you don't mind me asking...?" you squeak out.

Another smirk. Sans leans down to lightly graze his teeth onto your lips in a pseudo kiss, "...Since the day I met you, kiddo." He's back to his kneeling position again and is lazily pumping his thick member glowing in the dark. "Dunno what you see in a bony guy like me, but your passionate staring got me hot and bothered way too often."

You whimper at Sans' voice dripping with lust, instinctively closing your knees together to hide the fact that you're dripping even more just by listening to him speak. "Ah-ah..." Sans chastises you while prying open your legs again and moving his body between them. "I've waited this long. You're not hiding away from me anymore." You swallow hard and pant as you feel Sans taking his member in hand and rubbing it against your soaking wet pussy.

"You want me, and I want you. I'm going to _fuck_ you senseless until the only word you can utter is my name, and my name only."


	3. Completion

**Summary for the Chapter:**

> Once again, thanks to everyone for all the amazing and kind comments!! This completes the setup for this fic and the other chapters to come will be gratuitous smut. Please enjoy!

You can hardly believe that this is all happening. This morning, you had woken up thinking that today would be another, usual day. You'd gone to school to teach, played with the kids in the afternoon, cooked dinner... and everything came to a screeching halt when Sans made a move on you. The one, whom you thought your love would forever be unrequited, began treating you like some kind of goddess, showering you with pleasures you've never known until now.

And here you were. Lying on your bed, panting at the sheer need coursing through your veins. Your entire focus is on Sans looming over you, his phantasmal cock in hand and his one eye burning a vibrant blue. Though you've never had sex with anyone in your life, that didn't mean you've never experimented with yourself before. You've fingered yourself, played with some toys you secretly bought online... You knew that your body is ready, especially after that mind blowing orgasm Sans just gave you by eating you out.

Another whimper leaves your mouth as the cool member is rubbed against your clit and wet opening. Whether he's doing it on purpose to see your squirm or not, the way the blunt tip keeps slipping against the entrance and dipping in just a little to make your inner walls try to clamp down on it before it's pulled away is driving you insane.

"S-Sans..." you moan in frustration.

"Hmm? What is it, kiddo? Gotta tell me what you want," Sans smirks while continuing to rub himself on you.

You give a hint of a glare since you now know that he IS doing this on purpose. Still, no matter how bad the pent up frustration is, you can't muster the courage to verbally tell him what you want. Sans' dirty talk was definitely turning you on, but your throat is dry and you can't reciprocate. So instead, you act out what exactly it is that you want. The next time you feel the thick cock lightly breach your pulsating entrance, you move your hips forward to meet his movement. The gasp you hear as the tip finally enters into you is worth the dull pain you feel from being penetrated for the first time.

"O-Oh fuck...! Y-You really want me to bone you that bad, h-huh...?" Sans tries to snark. Obviously he's failing at it as beads of sweat form on his skull and you can feel his body shaking just from whatever sensations he's gaining from penetrating you. Sans seems to be trying to refrain himself from shoving the rest of his girth in. His expression softens in concern when he looks down and sees you smiling, but with some tears pooling at the corner of your eyes at the pain of being breached. "Hey... You okay? We can stop if you aren't enjoying this."

You shake your head as you feel Sans try and wipe away the tears with his bony thumbs. "No... I-I mean, it does hurt a little... but I'm just... I just can't believe this is really happening." You cautiously take one of his hands and nuzzle your cheek against it as you continue on, "Sans... I've been heads over heels for you since the beginning too... L-Like I said before, no human's ever liked me. And the fact that the one monster I fall in love with happens to reciprocate my feelings is just... I—"

No more words ever leaves your lips. Sans presses his mouth against yours in a pseudo kiss, slipping that ghostly tongue of his into your mouth to taste every last bit of you. Skeletal fingers are back on your body, brushing over protruding bones and your small breasts, the sensation causing you to gasp into his mouth and buck your hips even further. Sooner or later, Sans is pushing back into you. You feel the thick member inching farther and farther within you—deeper than any toy you've ever used on yourself—until you feel Sans' pants brushing against your bare buttocks.

Sans releases you from the kiss only for a brief moment for you to catch your breath, and once you do, he whispers in a husky tone, "...Kiddo, I can't tell you enough how _perfect_ you are. You're beautiful. You're amazing. And I love every fucking thing about you." And with that, Sans can no longer hold himself back and begins thrusting his hips, dragging his throbbing dick in and out of you.

Your head snaps back as you give a whine at the feeling of being completely filled. Yes, there is still some dull pain lingering, but the bliss of being thoroughly fucked—as Sans had vowed to do to you earlier—easily overpowered such pain.

"S-Sans...! Sans...! Aah, oh god, p-please, keep going...!"

"Nnngh, fuck, I wouldn't stop even if this house were on fire! Y-You feel so damn good!"

Each thrust is stronger than the last as you beg Sans to fuck you even harder. Every caress, every bite pushes you closer to your second peak for the night, and there is nothing more you can do, but hug the skeleton tight as he whispers back your name over and over. Wet sounds echo through the room as Sans' dick slips in and out of you, his pelvis hitting your ass cheeks providing a small dosage of pain to amplify the pleasure.

It's only when Sans gives a guttural growl and plunges his member in one last time that its tip hits your cervix at full force. You bite into Sans' shoulder—into his jacket, at least—as your peak hits you like a tidal wave and your entire body convulses at the powerful orgasm. It takes a few more thrusts on the skeleton's part while you're riding out your climax before Sans reaches his. There is burst of warmth in your lower abdomen as you feel Sans shiver and empties his load into you. Both of you tense up as each body relishes in its own orgasm before the tension washes away and the two of you collapse onto the bed. Heavy, hot breathing reaches your ear as Sans nuzzles your head and whispers your name over and over.

"...Damn. That... was amazing."

You give a small giggle and embrace the skeleton even tighter. You can still feel the phantasmal cock dribbling out a warm, thick liquid into your pussy. Where that liquid is coming from, you have absolutely no idea, but it's a wonderful sensation, and that's all you care about at the moment.

For minutes, Sans leaves himself lodged deep inside you as he languidly kiss you and caress your body. A shiver runs down your spine at the tender touches, to which your inner walls ends up constricting against the somewhat flaccid dick and massaging it back to its original hardness. A mischievous grin is shown to you as Sans pushes himself off the bed to take a good look at your crotch. "...Well. Looks like someone's needing some more attention. Would you like... another taste of the bone zone?"

"...I'd like that, actually," you smile back, giving a small giggle at that joke. "You did promise me an entire night of fun, after all."

Your teasing comment seems to have caught Sans off guard for a hint of blue blush appears on his cheeks. Sans plants one of his hands into his face to hide the blush and mutters something along the lines of you being a perfect tease. He then proceeds easily pull you up off the mattress so that you're sitting on his lap. The sudden shift in gravity plunges his now hard member into another part of your sensitive inside and you moan into Sans' shoulder at that feeling.

"All right, kiddo. I'm a skeleton of my word. Thank goodness tomorrow's Saturday because you aren't walking out of this room in the morning," smirks Sans as he begins to gently rock his hips into you, before the movement becomes more powerful and your mind becomes a complete haze.

Orgasm after orgasm, Sans continues to pleasure you through the night. Into the late hours of the night, the two of you continued to ravish each other on almost every inch, every wall of your bed room. You tried to reciprocate some of the feelings back at some point, though they still ended up with you crying out Sans' name in a mind shattering bliss. Eventually both of you reach the ends of your stamina and passed out under the sheets. Cleaning up could wait until tomorrow, was the last fleeting thought in your mind as you fell into a wonderful slumber in the arms of your beloved skeleton.

 

* * *

 

  
The next morning, Toriel stood in the kitchen in slight concern seeing that the human was not already up and about. Saturday mornings were when she would be up early to cook a nice breakfast for everyone, including the skeleton brothers, yet when Toriel went downstairs, there was no cheerful greeting or the smell of pancakes. She poured herself a cup of tea and enjoyed it while opening up the curtains in the living room to let in fresh sunlight, yet even then, the human had not come to greet her. After a few more minutes of contemplating what to do over the cup of tea, Toriel decided to go check up on her. Summer was slowly drawing near, and she hoped that the human hadn't caught a cold from the change in weather.

When Toriel reached the human's bedroom, she gave a quiet knock to see if there would be any response. Nothing. Now, Toriel was fully worried and she gently called out the human's name while slowly opening the door to take a peek inside. However, such worries vanished the instant she saw a most heartwarming—and a little embarrassing for that manner—sight. Leaving aside the pile of the clothes scattered about the room, Toriel couldn't help but smile at seeing the human snuggled deep into Sans' arms, the both of them fast asleep under the warm blankets.

It was such a peaceful and personal sight that the motherly monster quickly closed the door again. She didn't want to be intruding on something special that seems to have happened last night, yet she couldn't help but smile happily that something HAD happened. Toriel had seen the human and Sans practically dancing around each other, unsure of whether to make the move on the other for quite the longest time, so she couldn't be happier that one of them must've finally mustered up the courage to speak to the other about their feelings for them.

(Early Saturday morning breakfast can wait,) Toriel thought as she headed back downstairs. (Perhaps I should bake my dear a cinnamon butterscotch pie to commemorate the special occasion? Yes, that would be a lovely addition to this wonderful morning.)

Hearing the sound of Papyrus shuffling around coming from the first floor, the motherly monster decided to treat him to some morning hot chocolate so that he would leave the two upstairs alone. She hummed a cheerful tune while heading into the kitchen to whip up the hot drink with magic. Another pleasant turn of events had come about and she couldn't help but be happy for the slumbering lovers upstairs.


	4. Stuffed

**Summary for the Chapter:**

> Now that the setup is finally out of the way after three chapters, time for the smut drabbles to come! You've officially started going out with Sans and on weekends, you spend it with Sans over at his place. Papyrus is happy to give you two some privacy, so he goes off to hang out Toriel or Mettaton during that time, allowing you two to go at it without any worries.
> 
> First up, ghost dick expansion.
> 
> Also, many thanks to everyone leaving such nice comments! I do read every single one of them, and each one makes me so happy that I want to keep writing more chapters :D

Friday nights have become one of your most favorite days of the week ever since Sans confessed his love for you and you've begun dating him. Once you get out from work at the monster's school, you head home to grab some clothes for the weekend, stop by the store to get ingredients for dinner, and then head over to the skeleton brothers' house. Usually around the time you get there is when Papyrus is taking off to give you and his brother some well deserved privacy, and go have a slumber party at Undyne or Mettaton's place. Sans happily greets you, one thing leads to the next, and... well, it usually ends up with you two going at it in his room.

It's as if the both of you are trying to make up for the lost time of waltzing around each other, though you don't mind it one bit. Every moment you spend with Sans has been amazing and an eye-opener for you. You've even began to realize some sexual kinks you didn't know you had until now. And it just so happens that something Sans decided to try on you made you realize a new kink of yours.

 

* * *

  

Pants and heavy breathing echoes across the dark room. You've been itching for an orgasm for the past hour now, but it seems Sans is enjoying taking it slow for the evening. You are positioned face down on the bed with your butt raised in the air with Sans draped across your back as he languidly moves his hips at a agonizing pace.

"Saaaans...! P-Please, will you pick up the pace...?" you whimper out, trying to push your buttocks towards him. However, no amount of whining or trying to move your hips helps since he's pinning you down onto the bed with his full weight. It wasn't uncomfortable... just extremely frustrating.

After a few more lazy thrusts, Sans gives a contemplative hum. "You know... I just remembered something you told me that first night when I boned you. You said something about any bone I'd throw at you could never be too big."

You can practically hear him smirking as he says so, a hint of worry and a dash of excitement rushing down your spine. A quick glance to your right shows that the blue glow in Sans' one eye grows stronger, illuminating the dark room further. "Let's see how much you can actually take of another skeleton inside you," you hear him whisper as an unexpected feeling hits you from within.

"Sans...!? Wh-What're you doing—aaaahn!"

Only a snicker is returned from the skeleton pinning you to the bed. At first, you thought it was just your imagination, but you quickly realize that the pressure inside you is growing—the phantasmal dick is expanding in both girth and length, slowly pushing against your vaginal walls. It's a sensation you've never felt before and you cry out as Sans continues increasing his dick's size. "Mmm... That's it, kiddo... I know you can take more," growls Sans while the burning blue of his eye blazes stronger. "Tell me when you, nngh, can't take it anymore and I'll stop."

You whimper, moan, and sob as the ghostly cock keeps expanding, almost twice its original size already, yet you didn't want it to stop. Your pussy is practically dripping at the sheer sensation of being filled beyond any human could do to you, clenching harder and harder against the throbbing dick.

Just a little more... Just a little more, you keep telling yourself in your head. The feeling of Sans' hot and ragged breathing, combined with his small praises directed at you is absolutely wonderful, and you want make him proud. It's only when the member's length begins to push encouragingly at your cervix, rubbing at the tight entrance to try and coax it to open up that you're about to moan out for him to stop. But you're a second too late as the tip breaches through and at that moment, you see stars burst in your eyes.

"Aaaaaaahn! S-Sans, Sans!" you cry out as his dick plunges into your womb at full force. You ramble every curse you know of while hearing Sans gasp behind you as well.

"H-Holy fuck...! I-I didn't think you could take th-that much!"

The feeling of being stuffed to your max triggers orgasm after painful orgasm as your pussy is unable to clamp down on the rock-hard member anymore. Yet even then, you continue to be bombarded by pleasure with each small move Sans makes, especially when he picks you up onto his lap.

"D-Damn, kiddo... Aaaah, look at you. You look like you've grown a new bone."

Sans diverts some of his magic to bring over the full length mirror from the other side of the room and sets it right on the bed, making you take a good luck at your current state. Though your mind is in a haze, blood immediately rushes to your cheeks at what you see: Sans has your knees each in one hand to spread you wide, showing off the massive, blue cock wedged inside you. There is even a hint of it distending your lower abdomen.

But what sends the strongest shiver of lust down your spine is the predatory look Sans is giving you. Beads of sweat of pouring down his skull, his one eye is shining a vibrant blue with a hint of yellow near the iris, that look of raw hunger... You can no longer hold back your whimper as you grab at Sans' hands and begin begging to him like you've never done before.

"Sans, please _fuck_ me, oh dear god, please pound your cock into my pussy, I can't wait anymore, I need to cum or I'm going to go insane, please, please, _pleasepleasepleaseplease_...!"

And to such pleas, Sans answered with utter abandon. He roughly pushes you back on the bed with one hand under your belly while the other is on your back. You're back in the same doggy style position as earlier, though the difference being that you were now being thoroughly ravaged. Sobs of joy pour out your mouth as you feel Sans thrust in and out of you with no mercy, the slamming of his hipbone into your ass cheeks causing a stinging pain that only made you moan even louder. The bed underneath you two creaks louder every pound Sans makes, only to be drowned out by your loud cries of passion.

Dozens more times the engorged dick is shoved into your drenched pussy before you hear Sans grunt his peak. You reach yours seconds later as scorching hot liquid pours into you and spills out from the sides of your aching walls. A few more whimpers escape your lip while you feel Sans carefully pull out, and then, your mind slipped into darkness.

 

* * *

  

The sensation of something warm and a tad bit wet stirs your consciousness. When you open your eyes, all you see is a blur before your eyes begin to focus. There is moonlight coming in from the nearby window providing a gentle light to your tired eyes and once again, you feel that wonderfully warm sensation around your legs.

"Hey... You okay?" a gentle voice asks. You groggily look in the direction the voice came from and you find Sans with a wet towel cleaning your body.

"Sans...? What... Um...?"

"You passed out after you came. Almost gave me a heart attack, you know? Yeah, I don't have a beating heart like you do, but you still gave me a scare."

A few more wipes and Sans puts throws the towel onto his pile of socks in the corner of the room. He briefly uses his magic to get your pajamas back on before climbing under the blankets himself to hug you close. Hearing him sigh in content makes you smile as well.

"So, uh... I didn't go to far, right? You didn't stop me, after all."

You slowly shake your head at that and bury your face into his chest. "It was, um... r-really nice, actually... Didn't know I liked stuff lime what you did, Sans." Admittedly, being overstuffed has now been added to your list of shameful kinks. Then again, you didn't mind the addition since your beloved skeleton is the one who helped you realize it. "...I-I definitely wouldn't mind a repeat sometime."

Sans gives you a stronger squeeze with a small chuckle.

"I say it all the time, but god, you're perfect, kiddo. I love you and every bone in you."

"Me too. Still dunno what you see in me, but I'm lucky to have you."

Both of you giggle at that before closing your eyes and drifting off to sleep for real this time. You feel Sans brush a small kiss on the top of your head with a quiet, "I love you," to which you responded with your own, "Love ya too."


	5. Worship

**Summary for the Chapter:**

> So far Sans has been the one being in control, so might as well give the Reader take the reins for once. I know that other writers have written similar situations to this, but I felt like doing my rendition of it too.
> 
> Second kink: Light bondage, giving head, deepthroating, and some ghost hands.
> 
> Also, thank you once again for all the lovely comments! I'm glad you're enjoying how I write Sans :D

As weeks went by since you've started dating Sans, you begin to realize that you've never been given the chance to reciprocate to him during your sexual encounters. Yes, he's let you ride him and make him feel good that way, but never has he asked you to do anything like what you've seen online in those pornographic videos.

(This won't do,) you think to yourself as you boot up your computer and begin browsing some shops on the internet. Many websites and clicking on links later, you have an idea of what to do. With some final purchases made, you turn the monitor off and jump into bed with a smile. What you ordered will be here before the next weekend and you're going to give Sans a good time for certain.

 

* * *

 

When Friday night came, you gave Toriel a quick hug before bolting out the front door. A large backpack is on your back filled with what you ordered a few nights ago and you can't help the big smile forming on your face as you headed for the skeleton brothers' house.

Everything goes the usual way for the next couple of hours. You arrive at the brothers' house, you're greeted by Sans as he gives you a strong hug, you watch as Papyrus heads out with bags of spaghetti in his arms to receive cooking lessons from Undyne, a nice dinner is had between you and Sans, and the rest of the time is spent lounging on the couch together watching Mettaton's new show. Things only begin to change when midnight hits and Sans beckons you upstairs to his room.

After following Sans into his bedroom, you close the door behind you and take a deep breath. This is it. You're not sure how Sans is going to respond to the proposal you're about to give, but you muster up all the courage you have. Sans is looking at you curiously as he sits down on his usual, messy bed and you join him on it.

"What's up, kiddo? You look like you've got a bone to pick. Minus the negative meaning behind that phrase, of course."

You roll your eyes at that comment and give a small ahem. "S-So, um... Y-You've been really good about giving me a good time until now, and, u-um..." Mentally, you hit yourself and try to get the words out of your mouth. C'mon, you've practiced this! You can do it! "I-I-I was wondering if you'd, you know, be okay if I returned the favor."

A surprised look appears on Sans' face. However, it only lasts for a second before a mischievous grin takes its place instead. "Well, I'd be a bonehead if I said no to that... What did you have in mind?"

"W-Well..." you stutter out. It'd be faster to just show him at this rate, you think as you dump out the contents in your backpack that you brought upstairs. "...Whoa," is all that Sans says when he looks at the pile on his bed. Thick leather handcuffs, a bottle of flavored lube, some rope, a special throat spray that supposedly helps null one's gag reflexes... All in all, it is a small mountain of items that someone would use for BDSM. You're blushing bright red under your bangs as Sans curiously picks up the different items and checks them out.

"Heh, didn't know you were into this kinda stuff," Sans teases you. "I'd happily oblige if this is what you wanna try out."

"A-About that... so... w-would it be okay if I'm the one that ties you up...?" Your words are barely audible as you mumble so.

Sans seems to pause a moment to think about what you just said. He then twirls the leather handcuff with his finger before gently placing them in your hands. "Sure. I trust you. Can't wait to see what you've got up your sleeve for me," he smirks as he present his skeletal hands and wrists to you.

 

* * *

 

A few minutes later, Sans' wrists are locked together with the handcuffs and a rope is pulled between its chains to secure his arms above his head on the bed's headboard. Upon testing the rope to see how sturdy he it is, Sans gives a small wink to you in approval. You on the other hand have stripped down to just your underwear and used a few shots of that throat spray you bought along with the other items. The cherry flavor tastes a little strange as it coats the back of your throat, but you do feel as if it is numbing it a little... Hopefully it'll fully take its effect by the time you need it's help.

Now that everything is ready, you take a deep breath to calm yourself and then climb up onto the bed. You crawl towards Sans on all fours, blushing bright red considering how this must look to him. Shaking that embarrassment from your head, you give a small smile to the nice and bound skeleton as you push aside his knees to sit yourself in between them. Sans is staring intently at your every move, and when you get on your knees to plant a light kiss on his clavicle, you hear a gasp from above. Pleased at that response, you keep the ministrations going and nibble at that bone with your lips while using both hands to trace his rib cage.

More pants fall from Sans' mouth as you continue moving down. Small kisses are peppered down his sternum and you occasionally stop to suck on one of his ribs, causing him to moan loudly. Your fingers then move further to gently grasp and massage his spine, causing Sans' body to jolt. He instinctively tries to move his arms, but they are secured above his head, resulting in him whining at you to let him at least reciprocate the wonderful sensations. Unfortunately, this is your turn to pleasure him, so you give him a shy smile and shake your head.

With one last lick on the spine, you move your hands to hipbone and dip your body lower. A small kiss is planted on Sans' crotch over the pants. Thankfully, Sans picks up on what you're voicelessly asking for as his both his eyes go black before one lights up a vibrant blue. A bulge immediately forms under your lips, one that you've become quite familiar with lately. You pull down the black pants before you, freeing the phantasmal dick out. You then grab at the nearby lube and pour a hefty amount of it onto your hand to warm it up, which you quickly apply to the throbbing member. Hearing Sans hiss at the slick sensation of your wet fingers slipping over his dick encourages you even further.

You make sure that where you're sitting is comfortable before taking one last deep breath and trailing your tongue up the blue member from the bottom to its tip. Sans' body jumps again at the pleasurable feeling of your slick tongue, though your arms are wrapped around his waist to keep him from moving too much. You slowly lap at its full length a few more times to get a feel for how to do this properly, and then you take the bulbous head seeping a translucent fluid into your mouth, sucking on it like a frozen treat. It relatively tastes flavorless as you drag your tongue across the weeping slit, save for a small hint of saltiness to it. You shrug it off, just accepting that this is how it is.

While you are having fun sucking and licking at the thick member, what encourages you to try more is the curses and moans coming from above. Sans is desperately trying to buck his hips into your mouth, which isn't going to well since his arms are tied down and you have a full grasp on his lower body. His dick jumps a little each time you pump your fingers across the shaft, to which you can't stifle a small giggle.

Once you feel that you've gotten a handle on what you're doing, you swallow hard before moving on. The ghostly dick is throbbing and pulsating in obvious want of release. If you keep these ministrations up, Sans will definitely release his load before you finish what you've started. You look up at Sans one more time to see his blue-flushed cheeks and him being a panting mess. Then, you begin taking in his full girth.

"H-Holy fuck...!" you hear Sans gasp out through gritted teeth, yet you keep going. The spray you had used earlier seems to be working since you have no problem taking over half of the dick into your mouth, and then more as you force yourself to take the full length until part of it is down your throat. Tears well up a little at the corner of your eyes since breathing has become quite difficult, but you will yourself not to stop until your nose bumps into Sans' crotch. You still yourself when you've reached that point, trying to swallow the spit that's automatically formed in your mouth. Some ends up drooling out the sides of your lips, though what you do manage to swallow makes Sans cry out. Each time you try to breathe through your nose or swallow, your throat constricts, massaging the dick down your throat.

Not even one bob of your head is performed as Sans grunts his peak. The sensation of you fully taking in his length has triggered his orgasm, and load after load, you feel the hot liquid being poured down your throat. You close your eyes and fight every urge to cough or gag, breathing steadily through your nose until you can tell that the ejaculation is over and you've swallowed every last drop of the sticky fluid. When all that you can hear is Sans' heavy breathing, you carefully let the still throbbing dick out of your mouth. The cold night's air rushing into your lungs makes you cough a bit, but seeing Sans limp against the bed's headboard from post orgasm is worth the uncomfortable sensation still lingering in your throat.

"Fuuuuuuck... I can't believe you did that, kiddo..." you hear Sans whisper out, and you can't help the big smile that beams on your face upon hearing those words.

"I guess the website wasn't joking about that spray working. I didn't think I could go that far too."

"Well, I gotta give it to that human. Damn, that was amazing... So..." Sans trails off as he looks you up and down. His still glowing eye gives an ominous shine before you realize that something shoves you from behind, making you stumble closer to his lap.

You look back with a slight feeling of panic, and there you see something floating midair. They look to be a number of blue, glowing hands... A small yelp leaves your mouth as those hands capture your wrists while one stray one pulls aside your now drenched panties. The phantom hands pull you up just enough so that you're straddling Sans' hip and just as quickly as they had picked you up, they quickly push you down, right on the skeleton's member that is fully erect again. A sharp moan escapes your mouth at being stuffed full.

"S-Sans...!? I-Is this, nnh, your d-doing!?" you manage to whimper out as two other hands grasp hold of your hips and begins moving you up and down on the throbbing dick.

Sans gives a strained snicker. "Sorry, kiddo. C-Couldn't help but return the favor...!" His eye continues to glow brightly in the room as he controls the ghostly hands grinding you down on him. "My hands are tied, after all—literally!"

To anyone who looked in on what was going on in Sans' room, they would've been met with a most unusual sight. Sans' arms are bound and tied, binding him down in a sitting position at the head of the bed. At the same time, you are in no better shape for two ghostly hands have your arms locked in midair, while more are gripping your hips to move them.

Eventually though, the movement made between you two become highly erratic as each one tries to reach their peak. You are the first to come crashing down on a powerful orgasm, the time spent pleasuring Sans had been enough of a tease. You cry out Sans' name and bite into his clavicle to ride out the torrent of pleasure, and the tightening of your pussy's walls is what trips Sans over into his orgasm. He groans just like earlier as his hips spasm and his thick seed is spilled into you.

While your body is still trembling from the fast and hard orgasm, the phantasmal hands that had been holding your hips release and pulls your body away a little so that you're facing a smirking Sans. A blue tongue flicks out and traces your jaw as Sans growls, "So... you wanna untie me, kiddo? Your show of thanks got me all riled up... I gotta fully return the favor and give you a proper boning."

Blood rushes to your face again at that statement, to which you give a hasty nod. Your fingers tremble as they quickly undo the rope and handcuffs, your knees going weak at the thought of what Sans will do to you. The night was still young after all, and your lover had all the energy in the world to please you until you could take no more.


	6. Slumber

**Summary for the Chapter:**

> Still extremely ecstatic that people are enjoying my stories! I wanted to write one short drabble about the reader having a tough day and Sans helps you wind down.
> 
> Third kink: Sans helping you get off.

Today was only Tuesday and your week was already off to a rough start. Not only did you have to break up a fight that was started by a human child on one of the monster children, you had to have a rather heated argument about said child's parent of what happened. Thankfully, they came to understand that their child was the cause of the fight and apologized for the misunderstanding, but it didn't help lighten the emotional exhaustion that came with it. And then as you were walking home, it started pouring. You were drenched head to toe by the time you got back to Toriel's house and were greeted by a rather shocked looking Sans and Papyrus, who were over for dinner.

Papyrus quickly rushed you to the bathroom to take a warm shower while Sans ran to your room to get your new, and more importantly, dry clothes. You thanked them for their help after coming out nice and warm, sat down for dinner... and then, everything became a haze.

 

* * *

 

You remember eating dinner with the usual Toriel, Papyrus, and Sans, though your memory goes hazy past the cup of hot tea and slice of berry pie. There is a slight remembrance of your eyelids becoming heavy... Then feeling something warm on the side of your head.

For a few seconds, you remember the feeling of someone carefully picking you up into their arms and slowly carrying you upstairs. You swear that you saw a glance of Sans being the one doing so while he wished his brother and Toriel a good night.

The next thing you remember is a pleasant sensation: a feeling of someone gently petting your head. A small purr leaves your throat as you nuzzle more towards the hand, which feels rather bony even through your muddled mind. Heavy eyelids peek open and you see the faint image of Sans caressing your hair in bed.

"It's okay, kiddo... Just go back to sleep. Seems like you had one hell of a day," Sans whispers to you.

Your eyelids begin to close again at the wonderful feeling, yet when one of Sans' skeletal fingers accidentally brushes against your ear, a whimper falls from your lips. The hand on your head stops for a moment. It then cautiously traces the outer rim of your ear to which you can't help but moan quietly. A heated breath leaves your mouth at the tingling pleasure that runs from there to your groin... Ever since you had started dating Sans, you always relieved yourself of the day's stress before going to bed, and now that Sans was here with you, your body is instinctively reacting to his every touch and presence.

Even through your groggy mind, there is a hint of hesitation you sense from him. When he pulls his hand away and you whimper at the loss of touch, Sans speaks up. "...You want me to keep going?" You will yourself to open your eyes again and nod at his question. Your body is aching from release, and if he's willing to give it, staying awake for a while longer is worth it.

A light kiss is placed on your lips as you feel a pair of hands slip under the blanket and under your clothes. The slightly cold feeling of skeletal fingers on your abdomen causes you to shiver, however that chill is quickly replaced by a breathy moan. You press your forehead into Sans' chest as you feel the bony finger teasingly brushes against your pussy's folds, only leaving for a moment to pleasure your aching clit. The smooth texture of the thumb massages the small nub with enough pressure, causing bolts of electricity to rush down your spine.

The fingers continue to toy with your pussy, but it's only when one of the fingertips feels a moistness coming from within that Sans pushes one finger in. He's meticulous at what he does since he knows how you like it... Only the tip of the finger is inserted into your weeping pussy, languidly pumping just that one segment of bone in and out of you. Once every few moves, Sans pushes the finger a little further to scrape the fingertip across your throbbing walls. Sooner or later, the finger is fully moving inside you.

"Saaaans..." you moan out, gripping his other hand and panting hard against his jacket. The sensual movement is wonderful, yet your body aches for more.

"Shh... I know. Leave it to me," responds Sans, while pulling the one finger out. You can feel him rubbing another finger against your wet pussy, fully coating it with the natural lubricant before thrusting two fingers, then three fingers in.

"Aah...! Th-There...!"

"Yep, here. You like it when I touch you... lick you... and bone you here. C'mon, I know you're aching to cum..." you hear Sans whisper in a guttural tone. "Cum for me."

And you do, just as he commands. You bite your lip and shove your face fully in Sans' jacket to muffle the scream of ecstasy from being heard by anyone else but him.

Sans smiles as he watches your body spasm and your inner walls clamp down against his skeletal fingers. He continues moving the fingers a couple more times to help you ride out your orgasm, and when he feels your entire body go limp, he pulls them out.

You watch with half-lidded eyes as he licks his fingers clean. Normally, you'd be blushing at such a sight, yet you're exhaustion has finally reached its peak and you can't stay awake any longer. You want to reciprocate. You want to help him feel good too. But your consciousness is slipping into darkness too fast...

The last thing you hear is Sans reassuring you. "No worries, kiddo. You can help me feel good another day... You just go to sleep. That's a good girl..." Sans' soft voice and warm embrace is the last push for you to give in. All the troubles from the day are lost, and you fall into a blissful slumber in the arms of your most beloved and most caring skeleton.


	7. Tag-teaming

**Summary for the Chapter:**

> So, a typical random situation for hentai/yaoi stuff in Japan is a couple waking up in a locked room and the only way they can leave is by having sex. And considering that I needed some way to make the Reader and Sans okay with her getting banged by Underfell Sans was this scenario, so here goes a random Sans/Reader/Underfell Sans. Please refer to http://underfell.tumblr.com/FAQ in regards to what Underfell is.
> 
> Fourth kink: double penetration

This was supposed to be a usual Saturday morning, but ever since you started dating Sans, you realized that words such as 'usual" or "normal" were out of the question. Especially when you woke up sandwiched between two people—two Sans, to be more precise—and stuck in a mysterious white room with no doors or windows. Just as you were about turn around and wake up the more familiar Sans between the two, you see a flash of blue in the corner of your eye and a body flying towards the wall.

"Sans!?"

"Stay back, kiddo! There's no knowing who this impostor is!" Sans growls, his one eye blazing blue as he used his magic to pin the other one against the white wall. You quickly run to his side in confusion, all the while glancing back at the other Sans—the one clad with black and red, and has a one gold tooth in his pained smirk.

"Oh, so _I'm_ the impostor?" an eerily similar-sounding voice snickers back. There is a flash of red this time, and you give a small yelp as Sans picks you up into his arms and jumps back. A burning scorch mark is left on the ground where you and Sans had been standing—the other Sans' eye is glowing a fiery red and what looks like a giant goat skull looms behind him. "From my standpoint, _you're_  the bonehead who's the impostor... or are ya?"

"...What are you getting at?"

"Well, considering that kiddo looks awfully like someone I know... I say you're me, from another timeline. Sound familiar?"

Sans falls quiet for a moment before he responds back in words you don't understand, "...Another save?"

"Possibly a reset, but who knows?"

You glance back and forth at the two Sans in confusion of what they're talking about. Sensing your distressed gaze, the Sans you know gives a wry smile and then shakes his head before putting you back on the ground. The blue magic disappears as well, to which the other Sans also responds to by flicking away his own red magic. "U-Um... I don't get what's going on... b-but no more fighting? Right?"

The blue Sans nods and shrugs in his usual manner, while the red Sans has a shocked expression on their face. "...Heh, different timeline or not, I guess that kiddo never changes." With that, the red Sans begins nonchalantly walking about the room, possibly in search of a means of leaving this odd situation. The Sans you're familiar with also gives you a pat on the shoulder and joins the other one. You watch for a few minutes as they seem to have a quiet conversation of their own while checking each wall of the white room, to which the blue Sans smacks the red Sans from time to time, most likely because of what the other said.

Hating to not be doing anything, you join in as well. The white room is relatively simple: four white walls forming a square-shaped room, a large bed with some blankets and pillows, and nothing more, nothing less. It's only when you decide to check under the sheets of the bed that you discover something... A piece of paper with writing on it. "Um, Sans?"

""Yeah, kiddo?"" two sets of voices respond, taking you aback.

"O-Oh right, you're both Sans... Um, can you guys both come and take a look at this?"

The blue Sans reaches you first and begins reading what's written on it. You don't even have to look to know that his smile is getting more forced and strained per sentence he reads, though on the contrary, the red Sans standing to your right is smiling wider and wider. The following is what's written on the paper:

 

_[Congratulations for being chosen to participate in today's edition of "Escape the Room!"You have been trapped in a special room between dimensions and the following rules must be followed for you to return to your original lives._

_(1) The entrants of this room must have sexual intercourse to leave it._   
_(2) If there are multiple entrants, every entrant must participate in the act, or the door will not open._   
_(3) Oral sex does not count as sexual intercourse._   
_(4) Time is limitless here and waiting around will do nothing. Please be pro-active!_   
_(5) Trying to cheat the system will not work! We have had endless numbers of entrants who tried to cheat the system, but none of them have succeeded._   
_(6) Physical attacks done to the walls will not work. And please don't attack each other! We don't want any fighting amongst you!_

_With those following rules in mind, please have a wonderful day and happy fucking!]_

 

"WHAT THE FUCK!?" the blue Sans yells at the top of his lungs—yes, you know that he has none—unlike his usual calm and easygoing demeanor.

"Heh. Sounds like someone's out to have a good time," snickers the red Sans, who casually wraps one arm around your shoulder. Blue Sans quickly slaps that arm off, his one eye blazing a bright blue again.

"Hands off. You may be another me, but this one's not yours."

A sense of panic fills your mind as you see a burst of red appear in red Sans' eye as well. There's a part of you that's happy to have your Sans be so possessive of you, but if what's written on the paper is correct, this in-fighting won't help one bit. If anything, seeing either of the Sans getting hurt will pain you... so there's only one logical thing you can do.

You pull your shirt off.

Tossing aside the striped shirt and moving onto pulling off your jeans got the attention of both Sans rather quickly, for god's sake. As you sit back down on the bed and blue Sans rushes over to try and block red Sans' sight of your half-naked body, you just roll your eyes. "Sans... It already says on that piece of paper that fighting won't help. Might as well get this done and over with."

"Yeah, listen to the kiddo. Faster we get this done, the faster we can get out of this mess," red Sans' face practically beams in glee at your words. "C'mon, other me. If your kiddo's anything like the one in my time, then it's tibia-ssumed that she's a kinky little slu—"

Another laser strike to the ground, which barely misses red Sans. Heavy beads of sweat pour down his skull as he immediately shuts up and the other Sans exhales heavily. He turns to you and casts away that weapon he had summoned before asking you with a concerned expression, "Hey... are you sure about this? No regrets?"

"I-I'll be fine," you shrug back, your stutter making blue Sans look wearily at you. "Besides, the red one IS technically you, right? I'm, w-well, okay in that case..." You finish mumbling something about having a weird kink about wanting two Sans tag-teaming you, which you thought would never happen, as your face goes bright red at your admittance. You can feel both Sans' eyes completely glued on you after that statement and wish you could bury yourself under the blankets on the bed. Of course, such actions aren't possible for you're suddenly tackle hugged by two skeletons.

Red Sans hooks one finger under your jaw to try and steal a kiss from you, but he's denied the action as blue Sans yanks him down by his femur, he himself locking lips with you instead. Normally, Sans would take the time to be sensual and enjoy things slowly, though that seems to not be the agenda today... which you can wholeheartedly see why, since you can feel Red Sans kneading at your small breasts to try and get a reaction out of you. Blue Sans is definitely not in the mood of sharing. Still, the paper did say that everyone has to participate, so you let it be.

As a cold, blue tongue slips into your mouth to explore the wet cavern within, you become unsure as to what you're bucking and moaning at. The feeling of the tongue wrapping around yours is familiar and pleasant, while an intense sensation runs down your spine at two foreign hands pinching and toying with your already hard nipples. When the blue Sans releases you from the deep kiss and moves to trail light bites against your neck, the other Sans has already moved down tugging your panties free. Yes, your Sans has played dominantly and swiftly in the past, but he's never moved on this quickly as his other dimensional self.

Another sharp moan leaves your lips as one begins heartily eating you out while the other runs his hands all over your sensitive body. Each touch is amplified by the fact that you're being ravished by two lovers—a scenario that would never have played out in real life. Quickly, one thing escalates into another and as you see a glimpse of red diving into your soaking wet pussy, you feel familiar bone fingers being thrust in as well, making you cry out in abandon.

Even while the red Sans is licking and moving his tongue about against your constricting inner walls, he smirks. "Looks like the kiddo likes me eating her out over you."

Such a taunt is not left hanging as you feel the blue Sans pulls out the fingers within you, rubbing the engorged clit with his thumb before slamming the fingers right back inside to hit your G-spot. The sudden lightning bolt of pleasure hits you by surprise as you scream your first orgasm and feel yourself squirt—to your horror, all over the red Sans between your legs. The blue Sans gives a sly grin back while licking his wet hand clean, "...You were saying?"

You wish there was somewhere you could hide after cumming over the other Sans, but the red one doesn't seem to mind. There is a quick flash of a red tongue licking the fluid off his teeth, the rest of it being wiped off onto the bed's sheets.

"Not bad. You are _me,_  after all," the red Sans says as he sits back. There is a moment of tension as you see him unzip his fly and pull out his throbbing, red cock, but he gives a shrug back to the Sans behind you. "Hey, you got her off. Only fair if you get to bone her first. I'll just watch and enjoy for now, capiche?"

The blue Sans seems suspicious at the sudden cooperativeness of the other, though there's nothing he can do about it. A slight movement behind you tells you that he's also pulled down his pants, the cool feeling of his dick slapping against your ass. Your line of sight swiftly changes from facing forward to suddenly being seated upon Sans' lap. You bite back a moan as you feel him rubbing his thick member against your soaking wet entrance. However the quick thrust of his hips and the sheathing of his dick into you makes you cry out.

"H-Heh... Someone feels tighter than usual. Nngh, getting off on being watched, kiddo?" the blue Sans teases. "Yeah, you like that, don't you? You're squeezing tighter on me...!"

Sans continues to thrust hard into you while continuing to whisper dirty things into your ear. You bite your lip and nod fervently at every thing he asks, because it's true that you're getting off on this. It had been a fantasy of yours to be ravished by two of him, and now that said fantasy is happening, your body is sensitive as ever. You can even feel the red Sans sitting behind you, stroking his own cock as he watches intently at your pussy lips squeezing against the blue Sans' ghostly member.

More and more, Sans keeps pounding into you while grabbing hold of your ass cheeks with his bony fingers. You're lost in the pleasure showed upon you that when the red Sans makes a move, you're caught off guard. A sudden weight is added to your back and your eyes go wide at something blunt rubbing against your stuffed pussy. Even the blue Sans under you notices the added weight and pauses for a moment.

"W-Wait, wh-what're you doing...!?" you manage to stutter out, body tensing at the feeling of another cock teasing your pulsating entrance. However, the only answer you're given is a snicker as the tip begins to breach you. Both you and the blue Sans gasp at the added pressure of another slowly entering your pussy, the movement almost a crawl for the red Sans seems to have no intent of injuring you. Inch by inch, the member slips in. You're suddenly thankful for the fact that Sans had done his expanding dick trick a few weeks ago... otherwise there was no way that you could've handled two thick cocks inside you at once.

Once the red Sans is fully situated in you, he snickers and applies a light slap to your butt cheek. "I knew you could handle it... You're a kinky little girl in my world too, kiddo. Isn't that right? You're really kind of a freak, aren't ya?"

Only a whimper leaves your throat at those words, your head dizzy from the aching, but unimaginable bliss of being filled so much. Even though the red Sans behind you isn't the one you've fallen in love with, the same voice and familiar feeling member is enough to send your mind reeling.

Seeing that you're not hurt in any way—more importantly, the fact that you're enjoying every bit of this—the blue Sans under you drags his tongue under your chin into a deep kiss before beginning to move his hips again. The other Sans picks up on this pattern as well and joins in on the rhythm. In and out, in and out the two phantasmal cocks move. Each one hisses their own delight at your pussy's tight squeeze, only pausing when one of them felt as though they were about to prematurely cum. In and out, the rhythm continues until both Sans are slamming their hips into you.

"Oh god, I cant—! I-I'm gonna cum...!" you moan as the two thick, ethereal cocks plunge in tandem into your tight pussy. You're seconds away from reaching a powerful orgasm, but suddenly, both Sans stop moving. The lack of movement makes you whimper in need, when you feel both of them whisper into your ears.

"That's not our name, kiddo."

"You better be screaming our name if you wanna cum."

"You're louder than this."

"C'mon, let us hear you,"

"I know you can say it,"

"My lovely,"

"Little _slut_."

A strong shiver travels down your spine at that domineering tone, each Sans finishing the other's sentence. Pure lust ignites a powerful fire in your pussy as you cry out, "Sans, oh please, Sans, I'm gonna cum! P-Please let me cum, S-Sans, Sans, Saaaaaans!"

Both Sans give an identical chuckle. ""Good girl.""

It only takes a dozen more thrust as you're whimpering, moaning, screaming Sans' name as you cum. Hard. You sob in ecstasy as your entire body convulses at the wonderful feeling of being fully fucked and you feel scorching hot liquid being poured in. Even hearing Sans grunt and sigh from above and beneath you triggers another orgasm, the squeezing of your pussy forcing some of the thick cum out from between the two cocks. The feeling is utterly divine, and though you wish to enjoy it for a little longer, you feel your consciousness fade. Everything goes black, the last sensation you remember being two sets of kisses being rained down upon your cheeks.

 

* * *

  

A few minutes later—or perhaps hours later—you awake in your bed. Sunlight is pouring in through the window and you find Sans, your Sans, sleeping peacefully next to you. Slowly, the memories of what happened creep up on you and your face goes pale, then bright red. (Was that all a dream?) you wonder as you quietly sit up. (That was one realistic dream, if it was one...)

Despite your thoughts though, you immediately realize that what you experienced was no such thing. Your legs crumple under you as you attempt to get off the bed and you feel a sharp pain in your lower back. And more importantly, there is the distinct feeling of thick liquid seeping out from your crotch. A quick pulling down of pants and checking your panties shows quite a mess there of blue and red—the same red as a certain someone in that dream. There had to be a limit as to how red you could be blushing from embarrassment, but a familiar face suddenly being placed on your shoulder made you blush even brighter.

"Heh, well looks like that wasn't a dream... Mornin', kiddo. Rough night, eh?"

Oh, how you wish there was a hole in which you could bury yourself within! Not only did you enjoy the full attention you received from two Sans, you had no inhibitions of denying the other dimensional Sans at all. If Sans is holding your shoulder in that way he does when he's particularly feeling possessive and his voice is deeper than usual, it can only mean one thing.

A short yelp leaves your mouth as the sensation of Sans' blue magic pulls you back onto the bed. Both wrists are pulled above your head and pinned there by phantasmal hands, like the ones the skeleton had used on you before. You can only watch, in fear and in anticipation, as Sans straddles your waist and gently pets your cheek with his hand.

"Yeah, that was technically me boning you in that room, but you know... I've got a jealous streak in me too," the smirking Sans atop you says. He leans a little closer and whispers in a tone that is all too similar to the red Sans from last night. "I don't like sharing. And I want you to be screaming my name, and my name only this time."

A small whimper unconsciously leaves your lips as you nod.

Saturday has just begun, yet you feel as though you're going to be having a good—and bad—time.


	8. Domination

**Summary for the Chapter:**

> Well, I had multiple people interested in seeing another chapter of "Escape the Room", so I decided to go with it for this chapter! It took some thinking as to how I wanted to make this work, but I hope I have it figured out. As always, thank you so much for the comments...! Even just a simple "I love this!" is enough to make me smile and keep writing :D
> 
> Fifth kink: Roll reversal, BDSM, dirty talk, orgasm denial, foursome

A white ceiling. That is the first thing you see when you open your eyes. It looks awfully familiar and internally, you shake your head in knowing what this must mean. You cautiously sit up on the bed, and a quick look to your left and right confirms that your suspicions are true.

To your right is Sans—your Sans—sleeping peacefully, wrapped up in blankets. To your left is someone who looks shockingly like you, and another Sans—one clad in red and black, whom you remember all too well from the last time you were here—hugging another you tight and mumbling something about mustard.

This time, you shake your head for real. After a bit of careful maneuvering of the red Sans' hands away from the other you, you lightly tap the other's face to wake them up. A few light taps stirs her from her slumber and black colored eyes—unlike your hazel colored ones—open to focus on you. There is an apparent look of hesitation in her eyes as you bring up a finger to your lips to keep her quiet.

The other you nods in understanding before following you off the bed. She looks back at the red Sans to make sure he's not stirring, but seeing that he's burying himself deeper into the blankets, she gives a relieved sigh and sits across from you on the floor.

"So, um... I-I guess my Sans wasn't lying when he told me about you..." the other you says in a hushed voice. She fumbles a bit with the leather collar around her neck, which you are curious to ask about but you bite your tongue since now is not the time.

"Yeah... I wasn't expecting to end up here again too," you shrug, answering back in an equally hushed voice. It's odd to hear your voice coming from another. "I... take it that you know what this place is about then?"

Other you nods. "Mm, my Sans went on and on about it. Wouldn't let me out of bed for two days after that," she mumbles out while turning bright red and scratching her head.

"Yeeeaaah... Same here. For different reasons, I assume, but still."

You both nod in understanding. The last time you, your Sans, and red Sans ended up in this room, it had been quite an experience. And considering how domineering red Sans was over you, you can only imagine what goes on in the bedroom with him and the other you. Now that there are four people here, your body shudders a little at the thought of what may happen this time around. Whether that is from horror or excitement, you aren't certain... However, that thought does give you an idea.

The other you watches curiously as your eyes light up at the perfect plan, the best way to get back at these lovers for what happened after the shenanigans that took place in this room. You excitedly motion the other you over and begin telling her your plan. After the details are given, her eyes light up just like yours as she clasps her hands in a giddy way. She nods in acknowledgement before grabbing a bag that had been near the bed—when did that show up?—and shows you the contents of said bag.

A quick peak, and you have to stifle the laugh that almost leaves your mouth. Oh, this was going to be fun!

 

* * *

 

A few minutes later, everything is ready to go. You look to the other you one last time before you pull off the blankets and straddle your Sans, the other you mimicking your every move.

"C'mon, Sans. Wake up time."

"Saaaans... Wakey, wakey."

Two similar-sounding mumbles later, your Sans wakes up first. He mumbles a sleepy good morning to you, and it's only when he attempts to get up that he realizes that he can't move. "Um... Kiddo? Why am I tied up like this...?" He doesn't even have time to continue his question as a shrill, "WHAT THE FUCK!?" comes from next to him in contrary to the hesitant Sans under you.

You and other you can't hold it back any longer. Giggles echo across the room as you both watch each of your Sans struggle under their thick bindings. The blue Sans' hands are bound above his head with leather cuffs, similar to the ones you've ordered online before, with extra bindings tying him down to the bed's leg. The red Sans is in a much more severe state; his hands are bound above his head like the blue Sans, but his legs are also tied down to opposite bedposts at the foot of the bed. All in all, red Sans is fully bound down with no capabilities of movement whatsoever.

"Since we're all here this time in this room, the other me and I decided that we should have fun," you smile sweetly.

"Yep. It's about time we got in on this fun too," other you smiles in a way that seems darker than yours. "Let's lay down some ground rules, shall we?"

"No using of your magic, except for forming your dick with it."

"That means no phantasmal hands, capiche?"

"No controlling of our bodies too. We're the ones in control for this round, and you two have to play along."

"And if you break any of those rules..." other you trails off before leaning in close to her red Sans. "You get no release. None."

You seat yourself on blue Sans' hip and gently grind your crotch into his to reiterate, "And, I won't be coming over for a few weekends."

Seeing that both Sans understand that you two are serious about this, they gulp in tandem and return a weak nod. Normally, saying such things and being the dominant one is out of your comfort zone, but something about having the other you here is helping. You thought that she seemed quite like you at first, though such thoughts were pushed aside when she told you about her own personal kinks.

(The red Sans wasn't lying when he had said the other you in his world was a kinky little girl...) you think as you look over one last time to the other couple and find her stripping her clothes. Not only does she have the leather collar around her neck, her bony body is clad with risque lingerie as well. A leather corset, black laced panties, and even garter belts holding up her long stockings.

As much as you're captivated by the other two, you have work to do. The Sans under you's eye is already blazing blue and there is a familiar bulge pushing up against your crotch. (Well, better not leave him hanging,) is your last thought as your clothes are cast off as well. Your underwear isn't as extravagant as other you's, but it is a little more showy than usual: a black lacy bra and black panties that barely cover your crotch and your ass. You wanted to spice things up this weekend and it definitely had quite the effect on Sans... and it still is quite effective.

Sans' eyes are glued to you as you crouch down and begin by running both hands gently up his tibia. You keep your own eyes locked with his as you grip the femur of both his legs and pump them, in a way that mimicked your hand movements when you would jack him off. Another important thing you remember to do is let your small breasts brush against his bones as well as you snake yourself up his body; small as they may be, they still are soft and Sans loves the feeling of them on him. But what makes him grunt loudest is when you begin sucking on each part of his bones.

Your hot tongue laves up and down Sans' exposed femur, making him squirm under you. The bulge in his crotch bumps into your cheek for a moment while grinding up against his body, though you make sure to ignore it. Two fingers hook against the edges of his pants to pull them down, only enough to expose thick hip bones which you worship with your tongue and lips.

"Oh fuuuuck...! K-Kiddo, c'mon, don't tease me like this...!" Sans whines every time you feel a little devilish and lightly bite at the hard bones.

"Nope, I'm having too much fun here. Stay patient, Sans," you chide back. Your lips have moved on from his hip bone to his spine, making sure that you grip it tight, just how he likes it. "I know you're enjoying this."

Sans whimpers again, but does as told. He doesn't dare try anything that will result in no sex or fun times with you for weeks. He'd rather bear the embarrassment and being denied release than that.

A few more pumps of your fist on Sans' spine and the combination of bites and licks of his ribs, you hear the two next to you mumble an amazed, "Whoa..."

"Why didn't I think about trying that on you, Sans?" you hear other you tease the red Sans under her. "If other you is so sensitive to those touches... I wonder how you'll react?"

You take a quick glance in there direction and sees the red Sans panicking. He's instinctively using his red magic to keep his jacket and shirt on as if his life depended on it. Technically, he was breaking rules with using magic like so, but other you doesn't seem to mind.

Slightly empowered by the unexpected praise coming from the other two, you can't wait any longer and toss off your panties to grind your wet pussy onto his engorged member, resulting in both you and the blue Sans moaning in tandem.

You make sure to thrust in a few fingers into yourself to make sure that you're ready before pulling out the blue, phantasmal dick and situating yourself fully onto it. "Mmm... Oh, that feels goood..." you moan out as you sink yourself down on the member and sit on Sans' lap. Still, you make sure to keep your hip still and only flex your inner walls to knead the cool member. "H-Hey, no moving!" you sternly say to Sans, using your full weight to keep him from thrusting into you.

"B-But kiddo...!"

" _No._ "

Your tone makes Sans whine, but he does as told. "Good boy," you moan out as you lean down and at least give him a nice kiss.

"Aww, that's so cute... I think I need some attention now too," other you says. "Time for our fun, Sans." She gets straight to the point and yanks his pants off, tossing them off the bed. Nimble fingers quickly wrap themselves around the red, throbbing dick, pumping her fist languidly on the thick member to make red Sans groan. "You like that, don't you? I bet you want to take a peek at what seeing you tied up and helpless is doing to me."

Red Sans nods frantically, hoping for more than the tease that the other you has been until now.

"Well, I guess I can throw you a bone..." she whispers. Other you lets go of the seeping cock and stands up, making sure to keep both feet between the red Sans' hips. She sensually runs her hands up her legs before slowly pulling down her panties, a heated breath leaving her lips as she sees red Sans' eyes completely locked onto her crotch. There is a small trail of viscous liquid that bridges the cloth, which is quickly broken as other you chucks the panties behind her.

"Holy fuck...!" the red Sans mumbles, unconsciously tugging at the bindings keeping him down. "God fucking dammit, kiddo! You fucking tease!"

The other you chuckles softly before kneeling back down, giving the red Sans what must be a glorious view of her dripping wet pussy. "Like what you see? Of course you do."

And just like that, other you slides her body against the skeleton under her, intentionally rubbing her wet entrance against the throbbing member, resulting in a choked cry from the red Sans. She laughs and repeats the motion, though this time, she grips the dick and pleasures herself with it, rubbing the thick head against her clit.

"Y-You're gonna pay for this l-later, you little slut!" red Sans manages to sputter out, trying to buck his hips to try and penetrate the other you, but his body is too tightly tied down to the bed.

Other you continues to grip his red, throbbing cock and teasingly rubs it against her wet entrance as she smiles sweetly. "That's right, I'm your lovely little slut. You're the one that molded me into who I am, after all. Now... what are you?"

Though you are fully situated on your Sans, both of you can't help but watch in fascination of what's going on. Red Sans had seemed like such a dominant sadist last time you met him in this room, yet now he was reduced down to a blushing, flustered mess under other you. It's obvious that he's trying to maintain his demeanor, which is unfortunately slipping away quickly for him. Seeing that he won't say the words other you wants to hear on, she continues to tease him.

"C'mon... Is it that hard to admit it? Just say the words, and I'll ride you like there's no tomorrow..." other you whispers while licking her lips. "Don't you want to fuck me...? Jam that throbbing cock of yours into my dripping pussy? Fill me to so much with your thick cum that I'll be leaking for days until—"

"I-I'm your _b-bitch_!" red Sans finally yelps out, which makes you and blue Sans' eyes go wide. "Just—Just let me fuck you!"

"Well, that's a start..." she responds, bringing one finger to her lips to lick it sensually. "I wanna hear more, Sans."

"God f-fucking dammit...! I... I..."

"Hmm? I can't hear you?" One more grind down by the other you, and the red Sans finally breaks.

"I-I'm your fuck toy! Your play thing! Y-Your bitch that only gets to fuck you when you say I can! P-Please, for fuck's sake, j-just please let me fuck you! I-I need your hot pussy around my dick so that I can fill you with my cum and—aaaaaaaah!"

Red Sans cries out loud as you see his blazing red eye loll back and his head pounds against the pillow under it. The other you has shown him mercy and thrust the entire member into her tight pussy, though she does make sure to hold his hips down so that she is still the one in control.

There is a small shiver that travels up other you's back before she turns to you. "Other me, want to test which Sans cums first?"

Oh, that sounds utterly exciting! "Hell yes," you respond back as you lift your hip up and slam yourself down onto blue Sans' dick, which other you does as well, the cries of both Sans echoing through the room.

The feeling of the hot member filling you so full is wonderful. What adds the extra spice to all this is seeing your Sans hopelessly writhing under you and panting hotly at wanting more, yet not getting it at the speed in which he wants it. The world feels like it's spinning from the sheer amount of power you have over him. You test out new angles, new grinding of the hips to see what Sans responds best to, mentally noting down what seems to work.

On the other hand, there is other you riding the red Sans hard and loud. She seems adamant on getting him off before you, to which her Sans is desperately trying to fight against. He does seem like the dominant type and wasn't willing to lose to his other self in a match like this. Still, it seems like a losing battle as every word, every movement is driving him crazy. His moans turn into sobs as he begins screaming other you's name, bucking his hip as it seems he's hit his peak. The look of shame and defeat shoots an unexpected sadistic glee through you, and you can't help but cum hard against your Sans' pulsating dick, triggering blue Sans' release as well.

"Mmm... Oh, that feels so nice, Sans... Too bad you lost that round," other you also shivers, seemingly reached her first orgasm.

"Hey... other me?" you call to her as you pull out once to let the thick, blue cum drip down onto the still hard member.

"Mmhm?"

Once other you looks towards you, you slam your sensitive pussy back down on the wet dick to make your Sans cry out. "How about best two out of three?"

In contrary to other you's face lighting up in glee, you stifle another giggle seeing the red Sans under her go blue—not literally of course.

Quickly, the room is filled again with desperate cries and passionate moans. It feels like you and other you enjoy this room for hours on end and it's not coming to an end so easily like last time. At one point, you two were swapping partners to see if that would result in any changes. The inner sexuality that had been growing inside you had been released; there were no rules or boundaries here, after all.

After one final orgasm felt by everyone, your vision begins to fade. It seems the time has come to return to your worlds, and you lazily give other you a small kiss before all goes black.

 

* * *

 

When morning comes, both you and Sans awake in the usual bed at the skeleton brothers' house. There is an odd air about the room as you lie, blushing bright red, though Sans is in a similar state next to you with blue blushes lighting up his skull. Uncertainty and a hint of embarrassment hangs between you two until Sans finally speaks up, his voice cracking a bit.

"So... uh... about what happened..."

"Y-Yeah..." you manage to squeak out, remembering every bit of the debauchery that took place in that mysterious room between dimensions. Now that you've come to your senses, you want to bury yourself under all the pillows and blankets on this bed. You can't believe what you did there, and how much you enjoyed it all!

Hearing your small whimper of mortification, Sans turns towards you to gently cup your cheek and tugs your face to look at him. "Hey, it's okay... I mean, uh, it was unexpected that you'd get so... into it, but tibia honest, I-I enjoyed it."

"...Really?" you squeak again.

"Didn't know you had such a side to you, kiddo," he smiles back, the blue blush on his cheeks glowing even stronger now. "I wouldn't mind a repeat some time, heh... I-If you're up for it, that is."

You hear a click somewhere in your mind at seeing that embarrassed look on Sans' face. The embarrassment you were filled with quickly washes away and the smile that forms on your face can't be stopped as you roll over and straddle his waist. "Well, it is only Saturday morning... Wanna try now?"

The chocked gasp that comes from you trailing your fingers on his wrists is all that you needed as an answer. Mentally, you thank the other you for the wonderful time before jumping off the bed to go grab the restraints that you had used on Sans previously.


	9. Massage

**Summary for the Chapter:**

> Just a short, quick smut drabble of an idea that's been on my mind for a while.  
> Sixth kink: Nipple play

Ever since the monsters were freed from underground, the days went by in a flash. Days turned into weeks, and weeks quickly dissolved into months, winter being just around the corner. Since the monster children's school had entered winter break early because the town had become snowed in, you thankfully had more time to spend with Sans.

On one particularly snowy and cold day, you arrived at the skeleton brothers' house covered white and chilled to the bone, a result of the weather forecast being wrong about when the snowstorm was going to hit the town. Papyrus was currently busy trying out his new cooking techniques in the kitchen that Sans immediately led you upstairs and into their bathroom. He began filling the large tub with hot water and some bath gel to get the water all bubbly before turning to you, and helping you out of your icy cold clothes.

Once the tub was filled, Sans had you sit down in the blissfully warm water, which he quickly joined in as well.

 

* * *

 

And here you are now, sighing in relief as the bath begins to bring your internal temperature back up. You lean back and relax against Sans, who is seated behind you and rubbing your hands under the bubbles to get your frigid fingers warm again.

"I did say that I wanted to chill with you, but you turning into a popsicle wasn't really what I had in mind," Sans chuckled, his usually cold skeletal frame and fingers feeling warm for once because of the bath.

You roll your eyes at that bad joke, but continue letting Sans massage your fingers, then your arms. The feeling of blood rushing through your body again is delightful and his jokes are already too endearing for you to stop him.

Once Sans feels that you're no longer as cold as an icicle, he let's go of your arms and just holds you for a moment. Only the sound of water droplets falling from the faucet echo through the quiet bathroom, save for the banging and clashing coming from downstairs—it's a comfortable silence.

Just as you feel as if you could fall asleep like this, you notice that Sans is curiously peeking over your shoulder. Curious as to what's got his attention, you ask what's on his mind.

"Well... is it just me, or have your tits gotten larger?"

"U-Um, I-I'm not sure...?" you stutter out, surprised at Sans' comment.

However, your answer seems to not be enough for him. Sans moves the bubbles floating about away with his skeletal hand before bringing them both up to cup your breasts. The movement is gentle, but the hard metacarpals brush against your nipples, causing you to bite your lip to prevent you from moaning.

"Yeah. Definitely bigger than before. Didn't know human bodies could do that," Sans happily states. By the time that Sans is finally satisfied in measuring the size of your breasts, both your nipples are perked up and just the water splashing against it is enough for you to exhale hotly. And considering that Sans has been staring at your mounds for that long, he quickly realizes your current state and smirks. "Hmm... Are you bone-hard for me already?" he snickers while lightly pinching your nipples with his phalanges.

"Nnh....! Hey, you're the one who kept playing with my breasts—ahh...!" you moan as hard bones continue to squeeze and massage the throbbing tips. From time to time, Sans goes back to cupping your tits while toying with the nipples with the ball of his thumbs. The hard nubs are rolled, flicked, and pinched, causing your hips to buck uncontrollably—the movement of his fingers driving you wild, making you want to shove your hands between your legs and rub yourself off, yet you don't want to.

There is a strong warmth blossoming in your crotch that is travelling up your spine, to your nipples that are being toyed with. A few short gasps and an intentionally strong pinch later by Sans, you feel your pussy tighten and vision go white. Your mouth opens wide in a silent scream as orgasm hits you, the water in the tub splashing about because of your trembling body. Had it not been for Sans' hands holding you down, more than a few droplets of water would've splashed out from the tub.

As the strong peak begins to taper off, you go limp in Sans' arms. His hands are still gently kneading your tits, though they are much more subdued than before. "...Wow. Didn't think you could get off on just that," Sans chuckles as he kisses your cheek from behind.

Your face is flushed bright red now, a result from the combined effects of the warm bath, your climax just now, and the embarrassment of Sans' statement. You sink lower into the warm water as you mumble, "...It's because you're too good, Sans."

Sans stops moving for second, caught off guard by your response. A second later, he sighs and squeezes you tight with his arms. "...Kiddo, don't tease me like that. Pap's still here," he groans out. "You're making me want to take you to the bone zone, right here, right now."

At least revenge has been gotten by your words, now that Sans is hot and bothered too. "Hehe... Guess you're just going to have to suck it up and wait until later on when—"

"HUMAN! SANS! METTATON HAS SUMMONED ME, THE GREAT PAPYRUS FOR A RECORDING OF A COOKING SHOW! I SHALL BE BACK LATER! DINNER IS IN THE FRIDGE!" Papyrus' excited and loud voice unexpectedly echoes through house, followed by a loud bang that must be the front door being slammed shut. Once again, the bathroom falls quiet besides the drip drop of water droplets falling from the faucet.

You give a nervous laugh as you feel your body being spun around to face Sans, who has the most scheming smirk on his face you've ever seen. "You. Me. Bedroom. **Now** ," is all your hear before you yelp at being quickly carried out of the bathtub.

The small shiver that travels down your spine can't be stopped at the fact that Sans has learned of your capabilities of reaching orgasm with just nipple play, and also because of anticipation as to what he will do to you once you two reach his bedroom.


	10. Heat

**Summary for the Chapter:**

> As always, thank you everyone for all the kind comments! I never thought that my writing would be enjoyed by so many people, so I'm glad I started writing this Sans/Reader fic. (Much thanks to the person who suggested anal! You read my mind because this one has a bit of that!)
> 
> Seventh kink: Monster heat cycle, two skeledicks, double penetration of the vagina and anus

"Please, help my brother. He is back at our house underground and I can't do anything to help... You're the only one I can entrust him to."

Those were the words Papyrus had said to you one day during your lunch break at school. Toriel had called for you while you were reading under a tree, and when you entered the small conference room, you found Papyrus in tears there, as well as a concerned looking Dr. Alphys. Upon seeing you, he immediately rushed over and crumpled to his knees, clasping your hands and begging you for your help.

According to Dr. Alphys, Sans seemed to have entered a heat cycle similar to that of animals in the human world, and if Papyrus were to go anywhere near him, the taller skeleton's cycle will be triggered as well. Papyrus sobbed, telling you how much he wanted to help out his brother, but Sans had already taken off to the underground, former monster world. He didn't want Sans suffering alone, and that you were the only one he trusted him to.

The sobbing skeleton needed not say anymore. You quickly agreed to lend your help, concern growing with you as well. After Dr. Alphys gave you some more details on what this heat cycle was about and Toriel gave you her blessing, you set off at once. A quick stop by the house to grab some food, supplies, and extra pairs of clothes just in case, and you headed immediately for the path which was once blocked off by the barrier set up by human magic.

 

* * *

 

And now, you stand back in Snowdin, back in front of the skeleton brother's original home. You take a moment to catch your breath, since you had taken no breaks until you reached this place, your heavy breathing leaving white trails due to the cold weather here. One more deep breath, and then you turn the door nob of the house.

With a high pitched squeak, the door swings open. Thankfully, it had been unlocked—most likely because Sans didn't have any time to spare to lock it, and also because there are no monsters down in Snowdin anymore—and you quickly make your way upstairs. Though no one had been living in this house for months now, it is still relatively clean. The only evidence of someone being here recently are the scattered about objects on the floor; Sans must've bumped into them while staggering up to his room.

When you reach Sans' old bedroom, you quietly take a peek inside. If what Dr. Alphys told you about skeletal monsters' heat cycles is true word for word, there is a chance that his magic is out of his control, and because of his special abilities he may be unstable. However, such cautions did not deter you from your determination to help out your lover.

To your relief, you find Sans lying on his bed. Since he doesn't react at all to your opening of his bedroom door, he seems to be either asleep or unconscious... You rush over and put down your backpack before checking on him.

Even with his eyes closed, it's obvious that his magic is overwhelming him. A blue glow is concentrated around his left eye, and occasionally a trail of blue sparks out. Sans is breathing heavily, moaning from time to time through clenched teeth—he's definitely unconscious rather than asleep, you deduce, if he's in this much discomfort. You take out a towel and wipe away the beads of sweat pouring down his skull, hoping that it will at least make him feel better.

A quick look around also shows evident signs of Sans' heat cycle: wads of used tissue scattered about, splatters of blue liquid on his sheets, and most of all, the bulge that you see under the blanket over his crotch. You carefully peel that back to reveal a most surprising sight that makes your eyes go wide. Sans had told you before that because his phantasmal dick is made from by magic, he had free control over its shape. Still, what you find this time around is unexpected. Yes, his aching-looking, throbbing blue cock is quite familiar... had it not been for the fact that there are two of them.

Perhaps Sans had conjured up two in order to try and burn through his heat cycle caster? One looks the size of what you're used to, while the second one seems much thinner in girth, but about the same length. Both are dripping blue pre-cum and they twitch every time Sans takes a heavy breath.

—Well, time to get to work.

You go back to your backpack to grab some essentials. Some lube, drinking water, extra towels... whatever that may help alleviate the situation and make this easier for Sans. Your clothes are also cast off as you climb back onto the bed, the creaking of the frame not even stirring the small skeleton one bit.

"Don't worry, Sans... I'll try and help," you quietly say while pouring lube onto your hands. Sans has taken care of you so well all this time—now it's your turn to return the favor.

When your fingers slick with lube comes in contact with both of Sans' dicks, a lust-filled moan falls from the skeleton's mouth. You watch him as you use both hands to grip the two different sized members, and then pumping them in time with each other. Just that movement alone causes more pre-cum to dribble out from the tips, helping with the movement of your fingers.

What you weren't ready for though, was for Sans to suddenly cry out and release his first load only within a few pumps. You can't help but watch in amazement as sticky blue liquid shoots across the sheets, staining them even further. A repeat of the motion causes a second orgasm, connected into a third and fourth one, surprising you at how fast Sans is cumming. Though it's when his fifth load is released that you notice Sans' teeth chattering and he's whimpering... Your hand job helping him release more, yet causing too much stimulation and not making the orgasm worthwhile to put a break in his heat cycle.

(Well, that won't do... Dr. Alphys did tell me that he needs to undergo powerful peaks for it to help him. I guess I better step up my game.)

You pour some more lube onto your fingers, though this time, those fingers go straight for your pussy... and your ass. Sans had been wanting to try what humans call "anal sex" after he saw a girl getting double penetrated in her pussy and ass online by two males, and since then, you'd been training yourself to be able to add on anal play into your weekly sexual fun times with him. Thank god you have been doing those prep work because it's going about to come in handy.

There's no real need to prepare your pussy since thrusting in two fingers is already posing no problems. You pull those fingers out and then close your eyes while gently massaging your other entrance. The lubrication is helping with the process as you continue rubbing the tight muscle with the tip of your middle finger, only pushing in gently when you feel comfortable enough. A small sigh escapes your mouth as that finger easily slips in. Slowly, you move it in and out, wiggling the tip to loosen up your ass' muscles. When another finger easily slides in with the first, you pull them out and straddle Sans' hips.

(Don't worry, you can do this,) you mentally tell yourself. (Sans has already played with your ass a couple times with toys, so you can handle this.)

With one last deep breath, you first lower yourself onto the bigger member. The throbbing girth grinds against the sensitive walls of your pussy, making you moan at that sensation, but before you fully seat yourself on that thicker dick, you grab the other, much thinner one and align it with your other entrance. After a few rubs, the tip slowly slips in... and you situate yourself fully onto both dicks.

"Aaaaaaaah!" Sans suddenly yells out as his eyes snap wide. His left eye blazes an even stronger blue as you feel both members bulge against your tight walls, causing you to give a strangled moan. "Wh-What...!?" he mutters in a panicked manner, "K-Kiddo, wh-why're you here...!?"

It takes a minute before you can even respond; you have experienced double penetration before from the time you were in that strange room, but never have you taken one in each orifice. A few more gasps, and then you cup Sans' cheeks with your hands, "P-Papyrus told me the condition you were in... He a-asked me to help..."

There is a look of relief on Sans' face at those words, yet they disappear just as quickly. You already know what he's going to say next and silence him with a kiss.

"Sans... I know why you're trying to bear this by yourself. Dr. Alphys told me that you may be unstable... that you might accidentally lash out at me with your power..." you say without any hesitation. "It's okay... I'm willing to take on anything you do to me."

"But... what if I hurt you? Ngh, th-this heat cycle hasn't hit me in forever... I don't know what I'll do."

You can tell from how Sans is desperately gripping the sheets tight next to his body that he's fighting every instinct in his body to ravish you. The sentiment is touching, yet this won't do. After a slightly frustrated huff, you place both hands next to Sans' face and buck your hips, causing him to gasp out.

"Hey, I've dealt with your magical penis, another you from another world tag teaming against me, and even spent time conspiring with another me to pound you and the other you for hours," you mutter, each segment of your words being emphasized with a movement of your hips. "I don't CARE what you do to me. Now, fuck me already."

The skeleton looks into your eyes once more. Seeing that there is nothing but determination burning within them, he squeezes his eyes shut and mumbles out a short apology before you feel your body being slammed down against the bed. The sharp change in angle makes you cry out, the two members lodged deep in you hitting more sensitive areas.

A raging lust that is unlike anything you've ever witnessed burns in Sans' eyes, his ragged breathing more animalistic and guttural, that one last bit of hesitation completely shattered under your permission. Sans loses no more time from there. He gives a growl as he rakes his skeletal fingers about your body, hips slamming into yours in unhinged need and want. Usually gentle biting teeth sink into your neck, the faint twinge telling you that they've broken through skin, though you could care less at this moment.

You wrap your arms around Sans and sob in ecstasy bordering on pain, matching his rhythm as best you can. Having the ghostly cocks pounding in and out of both your orifices is uncomfortable at times, but even that is quickly lost. A dozen more thrusts and feeling Sans empty his first load into you triggers your lust as well.

Normally, Sans would stop there. However there is nothing normal about what is going on now, and Sans continues to slam into you even while the throbbing dicks are pouring out sticky cum. The added lubrication within you helps intensify the feeling as the cycle continues.

More thrusts. More cum being released.

Even more thrusts. And even more release.

At times, Sans forcefully pulls out only long enough to change positions. Hands—his own and his phantasmal ones—are once again all over you as he thrusts his members back in. He pushes you against the maroon colored wall, your back scraping against it each time he bucks into you. Once every few thrusts, skeletal teeth rub against your lips and a blue tongue is shoved in to map out your mouth, as if slamming his dicks into you isn't enough.

Somewhere in your lust hazed mind, you can't help but smile. You've never seen Sans let go this far. Truly being ravished—dominated, for that matter—like this fills you with so much joy. Seconds turn into minutes, minutes turn into hours. Sans has cum within you multiple more times and his never ending seeming heat continues to drive him on... until the end finally comes.

You had been sobbing in over stimulation as Sans fucked you doggy style from behind, your resolve slightly wavering at your own stamina reaching its limits. Your vaginal and anal walls were both squeezing hard down on the phantasmal members as another overwhelming orgasm wracked your body, until Sans gave one final growl. The feeling of his body trembling as he spilled his seed deep into you again could be felt before the full weight of his body crashed down on yours.

"S...Sans...?" you barely whisper out, voice hoarse and dry from all the screaming done. All you hear at your ear is Sans' heavy breathing, which begins to slow and eventually turns into soft breaths. "Sans... Are you... okay...?"

No answer is returned. In contrary to the way Sans had been breathing when you first found him, no longer do you hear the labored pants or gritted teeth.

Your entire body is screaming from the extensive work Sans had put you through. Still, you muster enough strength to carefully move the passed out skeleton off your back and onto the mattress. Thankfully his ethereal cocks have dissipated after his final orgasm and you don't have to worry about pulling those out—though you decide to ignore the globs of liquid pouring out of both your orifices for the time being since there is nothing keeping them trapped within you anymore.

Although Sans looks utterly exhausted, the blue blaze in his eye seems to be gone. The beads of sweat that were pouring down his skull are drying off as well. All in all, it seems his heat cycle has finally passed. A sigh of relief leaves your body all the while collapsing next to him.

...You did it. There's no doubt that the lower half of your body is going to be in pain for the next week or so from the chafing that happened, but it was worth it all. Those are your last thoughts as you pull a nearby blanket over both you and Sans before nuzzling at his side, slipping into a blissful slumber.

 

* * *

 

Warmth and the sound of water is what eventually wakes you. Heavy eyelids slowly open to find that you're sitting in a large bathtub filled with warm water. Your mind wonders what you are doing here, unable to register the change in scenery compared to when you passed out.

"Hey..." a voice gently calls to you from above. You tilt your head up and see a familiar face—Sans.

Noticing that he is cradling you sideways in his arms and on his lap, you lift your hand out of the water to caress his cheek. "Hey... Looks like your heat cycle's over, hm...?" you smile back, still tired but feeling contented.

Sans gives a wry smile and nods, "Honestly... I was hoping I'd deal with this alone." Skeletal fingers warmed up by the bath carefully trace parts of your shoulder and neck where there deep bite marks left in them. "...I thought I was gonna break you."

"Well... you did do a number on me... but remember what I said before...?"

"...?"

"No bone you throw me can be too big... Remember...?"

Sans' eyes go wide at those words, cheeks turning bright blue as he gives an embarrassed groan. He shakes his head and squeezes you tight, "...Kiddo. I swear, you're make my non-existing heart melt way too much. You're too perfect."

You giggle in response before you give a yawn and lay your head back on Sans' rib cage. "Well, if you're all better... then I'm gonna go back to sleep..."

"Yeah, you do that, kiddo," Sans whispers while planting a soft kiss on your head. "You took good care of me, so I'll do the same for you. Leave the rest to me."

One last nod and you let your consciousness slip away again. Leaving aside the fact that you're going to have to come up with some explanation to all the bites on you to Toriel, or the fact that you won't be walking straight for a week, for once in your life, your heart is filled with a sense of accomplishment, confidence, and most of all... unfathomable love for the skeleton monster holding you in his arms.


	11. Change

**Summary for the Chapter:**

> I wanted to change things up and add something to this story that'll allow me to explore more kinks. Considering the fact that there were humans who were able to use magic, my headcanon is that a person who has been under the influence of monsters for very long periods of time gains the ability to wield magic as well. Sorry, no smut for this chapter!

Your life since the breaking of the barrier trapping monsters underground has been quite wonderful. Upon deciding that you didn't want to return to your previous life, Toriel took you in as her own daughter and you now teach at a school dedicated for monster children. You are in a steady relationship with the love of your life, Sans, whom you thought your feelings would forever be unrequited. All in all, everything was great.

Thus when the sudden change happened in your life, it sent you into a flurry of a panic.

 

* * *

 

The alarm goes off in your room like any Wednesday morning. It always rings around 6:30AM so that you have enough time to cook breakfast, pack lunches, and then head off to school with Toriel. Usually getting up at such an hour isn't a problem...

However, the ringing of the alarm causes a overwhelming migraine unlike anything you've experienced until now. You give a pained groan as you shut off the alarm and try to get off the bed, the pain so horrible that you crumple down to the floor for a moment.

Could it be that you've caught a cold? The room feels as if it's spinning and you barely make it to your dresser to wash your face in the small bowl kept there. The pain seems to subside for a moment when you splash the cool water on it, though it's still painful enough for you want to throw up.

After managing to wash your face and calm down, you grab the nearby towel to wipe up and look up into the mirror before you.  
For a few seconds, you stare into your own reflection. Your hands begin to tremble and the towel you were holding falls to the ground. Everything, save for one part of you, is the same, the one exception being your right eye...

It is colored a fiery _blue_. Your iris is no longer black, but a blazing yellow.

You can't hold back the scream that echoes through the house.

"My dear, what's wrong!?" a panicked voice calls from across the hall. You don't even hear such words as you stumble back towards the bed, one hand clutching over your eye. A small trail of blue follows your every move though, and you trip over your belongings on the floor at that sight. Still, the pain of falling on the ground is miniscule compared to the pain shooting through your skull.

Your mind is a flurry as you hear a frantic knock at your door. Toriel is calling to you, worried about the previous scream, but your mind is reeling in a panic.

What was going on? You've seen Sans and Papyrus' eye light up as such when they're using magic, but you're just an ordinary human. Things like flaming eyes aren't supposed to happen to you! Are you ill? Is it fatal!?

Tears well up in your eyes at that thought. The aura emmanating from your right eye grows stronger and within a blink of an eye, something lashes out at the objects in your room. Even more fear swells in you as things are smashed against walls, the pain combined with the unknown making your sob.

By the time Toriel manages to unlock your door and enters, she gasps at what she sees. Your room is a mess with remnants of blue scattered across it, and you, cowering in the far corner of it. "My child...?" Toriel whispers at the sight of your discolored eye.

Another sob falls from your mouth in tandem to a flash of blue. Toriel instinctively uses her magical flame to cast down the jar that flew towards her.

"I-I can't—I can't control it... Wh-What's going on, T-Toriel...?" you whimper as your brace yourself, hoping that it would stop whatever is happening.

"Magic... But how...?" you overhear Toriel muttering to herself. Her confusion is quickly resolved as she looks back to you with an encouraging smile. "Breathe, my child. Try and stay calm... I'll be right back, okay?"

You want Toriel to stay, to comfort you, but you don't want to hurt her either... There's never been a time when you've been so glad that she was a monster with powerful magic until now, or else, whatever you're doing would've injured her. When Toriel tells you once more that she will be back quickly, you fight back more tears and nod.

As Toriel rushes out of your room and downstairs, you squeeze your eyes shut tightly. The pounding in your head is still horrendous, but you keep telling yourself that everything will be okay. Toriel has protected you thus far. She'll never go back on her word...

Seconds turn into minutes. Minutes almost turn into an hour. Your bravery slowly begins to slip, the fear creeping up on you making your blazing eye stronger when—

"Shh, it's okay, kiddo," a comforting voice says to you, accompanied by a gentle hug. "C'mon, no need to cry. Went through what you're going through myself, so don't worry. You're gonna be fine."

A sense of relief washes over you at the embrace. You want to cling to him—to Sans—and believe his words, but you're frightened that you'll lash out at him with whatever power you suddenly have. "S-S-Sans... B-But...!"

Sans pats your head before kneeling down and cupping both your cheeks, taking a good look at your eye. "Heh. I know you have a thing for me, but you didn't have be such a copy-cat. Well, you're a human, but you get what I mean." That lighthearted tone is enough to at least let a small giggle leave you while sniffling. "There's my cute kiddo. Your skull must feel like it's about to burst, eh? Can you hang in there a little longer?"

You nod at Sans' words. Seeing him has reminded you that the color of your eye at the moment is similar to that of his when he's using magic, and somehow that connection puts your mind a bit at ease.

"Alright, I'll make it quick," Sans says while carefully picking you up off the ground and cradles you in his arms. "Toriel, I'm gonna take her to Alphys. Pretty sure our scientist can give us some more insight."

"Please. Thank you, Sans," you hear Toriel respond in a concerned tone, to which Sans nods back to. There is a flash of light, and just like that, he and you teleported from Toriel's home to Dr. Alphys' lab nearby.

 

* * *

 

After some special medication and blood tests later, your eye has finally gone back to its original color and the migraine has subsided as well. As you are laying in one of the patient beds in the lab and enjoying the fact that you are without pain while Sans holds your hand, Dr. Alphys comes in.

"W-Well, I-I'm done with the tests... Very interesting results, i-if you ask me," she says while flipping through the chart in hand.

"Interesting... how?" you ask. "I-It's not bad, is it?"

"O-Oh, no! Not at all!" Dr. Alphys exclaims with a smile. "I-I mean, I've never seen this before, b-but considering that humans were capable of m-magic, this isn't too much of a surprise..." She hands the chart to Sans, who begins looking at the notes on it. "Anyway, congratulations! ...I-I think? You're more monster than human now!"

You feel as if your brain halts at those words. "...Excuse me?"

"Your numbers are off the charts. The f-fact that you're able to use magic supports them!"

Your mouth hangs agape at Dr. Alphys' statement, shocked by this sudden turn of events. First, you wake up with the world's worst migraine. Second, your eye starts doing the thing similar to that of Sans'. Third, the monster scientist tells you that you're more of a monster now. While unsure as to what to say, Dr. Alphys continues on.

"I-It seems you're body's b-become too accustomed to being around u-us monsters. A-Another hypothesis could be... w-well... you ARE in a relationship with Sans, s-so..." the doctor's face blushes red while trailing off.

As dull witted as you may be, even you can tell what she's hinting at. You quickly look to your left at Sans, whose entire face is bright blue from embarrassment—he being the most likely cause of all this, after all. Your face is stuck in an embarrassed smile as you hear Dr. Alphys in the back ranting something about this being just like the anime she's watched.

"So uh... H-Heh, I guess this is my fault...?" Sans nervously chuckles. "Too much bone zone?"

"SANS!"

"What, Alphys knows already. She's the one who filled you in on my heat cycle problem, after all."

"Yeah, b-but still..." you mumble back. Having a doctor telling you details on how to help out a loved one's problem is one thing, but openly discussing it in front of them was another.

"A-Anyway, you're good to go. I-I've got some, u-um... Oh yes, f-files! Files to take care of, so I-I'll leave the rest to you, Sans!" And just like that, Dr. Alphys was gone.

Sans shakes his head before lending you hand to help you get off the patient's bed. "C'mon, I'll take you back home. This day's getting too _humerus_ for me."

You roll your eyes at that comment, but accept Sans' hand. It feels nice not having that pounding pain in your head anymore as you slowly walk through the lab with him. "So... What now?" Learning that your condition isn't fatal is great, though that doesn't solve the problem of this new predicament that's been thrown to you. There's no knowing when your new earned power may run wild again like it did this morning.

Picking up on your worried tone, Sans gives a huge grin back. "No need to look so _sternum_ , kiddo. I'm a _bonefide_ blue magic wielder. I'll teach you the ropes."

Now THAT is a new pun you've heard. You can't hold back the giggle at his jokes and squeeze his bony hand back in acknowledgement. However, there is one more thought that pops in your mind...

"Hey, Sans?"

"Mm?"

"If I can eventually use the same magic as you... does that mean I can take you to the bone zone myself too?"

Sans almost trips on his own feet at that comment. He manages to mumble out a "Let's just start you off with the basics," before rushing on ahead, his skull bright blue again.

This time, a loud laugh leaves your mouth as you quicken your pace and catch up with the blushing skeleton. Things keep changing rapidly in your life... and you like it that way.


	12. Training

**Summary for the Chapter:**

> Time to put that magic the Reader can use now to good use! All the thanks to the people who keep leaving comments...! I think I'll be incorporating some kinks for Sans in future chapters, now that most of the setup for the Reader is ready.
> 
> Eighth kink: Mutual masturbation

Concentrating on one thing for long lengths of time has never been your expertise. Reading books and cooking are the two things that you are able to maintain your focus, but those were your hobbies. Trying to stay focused on a subject or act that has been foreign to you until now is proving to be quite the feat.

"Okay, kiddo. Try again."

You crack your neck and pop your shoulders before nodding back with a serious expression to Sans sitting a few feet away from you. It takes a few deep breaths to calm your mind enough to remember what Sans has taught you. Concentrate on your core, imagine it as a physical form, and manipulate it before you...

There is a burst of blue as your eyes snap open. You can feel your right eye burning with a phantasmal flame, a sensation that you're slowly getting used to thanks to the training sessions with Sans, and once you have a grasp of that power, you muster up your imagination.

—A hand. One that is similar to yours, just detached from your body...

"There you go. Keep at it," Sans encourages you on as a phantasmal hand begins to form before you. "Stay focused. Try moving it once you're ready."

You think back to the example the skeleton monster had shown you earlier and suck in another breath. The solidified, blue hand's form wavers for a split second, yet you keep your eye on it as you try to move it.

Sans has placed a cup filled with blue liquid made with his own magic—for reasons that will become apparent in a few seconds from now—a foot or so away from you. The ghostly hand moves more gracefully than the previous attempt, the blue fingers wrapping around the cup to pick it up. However once the cup rises into the air and moves forward again, the sound of kids laughing outside catches you off guard and your concentration waivers—

That is all it takes for the magical hand to disappear. The cup crashes to the ground, spilling the liquid within it.

"Aww, you almost had it, kiddo," Sans smiles as he snaps his fingers and the spilled liquid disappears with a small poof.

You can't help the heavy sigh that leaves your mouth as your eye returns to its original color. These training sessions have been going on for quite some time now, yet you're still having trouble getting a handle on your new power. Unlike how Papyrus and Sans' magic works, you are unable to take control of other people's hearts and is currently limited only to creation of objects with it. Manifesting bones also made sense for the skeleton brothers since they're... well, skeletons.

The same does not apply to you, unfortunately. However, remembering how Sans created phantasmal hands during your fun times struck a chord with you, and that is what you decided to focus using your magic with. Training it has been quite rocky though as you sigh again. "I'm sorry, Sans... I've got such a short attention span."

"Don't worry about it, kiddo. You're doing great," Sans smiles back, filling the cup once more. "A monster's born with their magic and they learn to use it over skele-tons of years. You just got yours, so just take your time."

"Yeah..."

"But attention span, huh? Hmm..."

You continue the training a few more times as Sans seems lost in thought. At one point, the hand manages to get within inches to the sitting skeleton, though a random fleeting thought causes the hand to throw the cup and crash against the ceiling. The only saving grace being Sans dissipating the liquid before it splashes on either of you.  
After that mishap, a huge grin appears on Sans' face. You know that look... It's the same one as when he's come up with some new ideas to try out during your intimate times.

"Kiddo, I know the best way to keep you concentrated."

 

* * *

 

Once Papyrus leaves the house later that night for his weekly filming of the cooking show on Mettaton's program, the smaller skeleton excitedly ushers you back upstairs back to his room. He immediately pulls out the special box of toys that has been accumulating over the past couple months and rummages through it, eventually deciding on the leather cuffs you had bought for him.

"S-Sans... Are you sure this is going to help...?" you ask in a worried manner as Sans hums a happy tune while binding your arms above your head on a rather conveniently placed hook on the wall. He makes sure to put a cushion under your butt, before pulling off your pants—pulling off your pants!? "U-Um, wh-what're you doing?"

"Don't worry, I know what I'm doing, kiddo," Sans says, making sure that you're comfortable. He takes a seat himself across the room on his bed's mattress, the look in his eyes is mischievous and ominous in a way.

As you wonder what Sans is up to, your breathing hitches a moment when that fiery blue returns to his left eye, a familiar bulge forming at his crotch. Eye contact is kept with you as one skeletal hand pulls up his shirt, the other moving down to pull down the pants to release his ghostly dick out. You can feel your eyes go wide at the sight, watching Sans' every move from him trailing his fingertips from the bottom of his member to its bulbous tip. Your knees instinctively shut at the sight, your nether region clenching together at the lovely sight.

"Heh, like what you see?"

You nod fervently at Sans swiping his finger at the tip to show off the viscous precum. Since you've been training with the skeleton non-stop since your visit on Friday, there hasn't been any intimate time with him.

"Well, you're going to keep watching," Sans murmurs, licking his teeth in an insinuating manner. "You're free to touch yourself if you want though..." He snaps his fingers once and summons one of his phantasmal hands, the thick blue finger tugging down your panties and brushing over your sensitive clit for a moment.

The moan that leaves your throat is needy. If your hands weren't bound over your head, you'd be touching yourself or tackling Sans to ravish him. But you can't, no matter how much you want to. All you can do is keep watching as Sans languidly pumps his dick, the blue blush adorning his cheek and the hot pants leaving his mouth making you burn with lust.

"Saaaaans..." you whimper, hoping he'd at least unbind you.

"C'mon, kiddo... Mm, I know how much you want it. All you gotta do is touch yourself... Just get yourself ready, and I'd be happy to bone you like I always do. Don't you want this in you already? You better hurry or... nnnh, I'm gonna finish myself off at this rate." Sans is pumping his dick stronger now, the dripping precum lubricating his fingers and making slick noises echo through the small bedroom. That combined with his small moans drive you crazy enough that you remember something important.

A quick shutting of your eyes and immediately your right eye turns the same blue as Sans'. You concentrate harder than any attempts during your training to conjure your own magical hand that you take no time in plunging into your dripping wet pussy. The phantasmal hand work their magic—no pun intended—as if it's no different from your own, gently curling at the segments of your digits to massage the parts of your wall that are most sensitive.

"There we go, you're doing it. Mm... Now that's a sight I can get myself off to as well. That's a good girl... Keep moving those fingers. Stretch them so I can get a good view."

You do as Sans says and move the hand at your crotch to spread your puffy lips, drinking in his praises. However, no matter how much you keep thrusting in those ghostly fingers, you just can't move them as well as your own. It's proving too hard for your to reach your peak. "S-Sans... P-Please, I-I can't get myself off...!" you whine in need.

"Well, you HAVE been doing an excellent job so far..." smirks Sans, still stroking himself at seeing you so desperate.

...Okay, that is it! Yes, you feel a lot more comfortable with using your magic, yet Sans has tortured you enough this way. There is a trail of stronger blue as you glare towards Sans and conjures up another hand—one that grabs his dick, making him yelp. Your breath hitches again while you force one more hand to appear, pulling Sans towards you. It's getting painful to keep all the hands manifested, but once you drag Sans across the room and manage to get his hard member to penetrate you, the headache was definitely worth it.

The feeling of the familiar dick slamming in to its hilt along with your own magical hand's fingers finally helps you reach orgasm as you cry out in ecstasy. "Aaaaahnn... Ohhh, that's much b-better..." you moan, your body jolting as the waves of pleasure courses through it. It looks as if Sans wants more and is desperately trying to move his hips into you, though you're having none of this. The hand that you summoned that pulled the skeleton over to you is now pinning him down, not allowing even centimeter of movement.

"Uh... Kiddo? M-Mind moving your other hand off my back...?"

"Nope."

"...Huh?"

"I'm finally starting to get a hang of this magic stuff. Time for me to have some fun too," you smirk back, the blaze in your eye growing stronger. Another giggle leaves your throat as you hear Sans gasp and attempt to look around in confusion.

Since you no longer need the hands touching you, those ones near your crotch disappear for a moment only to materialize again under Sans' shirt, running fingers across his sensitive ribs and spine. Seeing him squirm without being able to move is quite... exciting for you. You can't help yourself from creating another, and another hand to continue making Sans writhe before you, the pleads for wanting to cum only encouraging you further.

Sans was right when he said he had a good idea; this DEFINITELY is a much more effective and fun training method for maintaining your concentration. A big smile forms on your face when Sans whines, groans, and moans his forced orgasm, you just enjoying the feeling of him spilling his seed in you.

"...Hey, Sans?"

A whimper of acknowledgement is returned.

"Considering that I got my magic from being boned by you... does that mean the more you cum in me, the stronger my magic will get?"

Sans freezes with a forced smile like a deer caught in headlights at that comment. That reaction alone is all you needed.

You dissipate all the other hands save for one so that it can release you from your bindings. Once your hands are freed, you immediately push Sans down to the ground while he's still lodged deep inside you. Mounting him like this would've never crossed your mind a few months prior when you first had sex with him, but just as Sans has changed over time, he's helped change you as well.

A small kiss is planted on his teeth before whispering, "...I can't wait until I take you to the bone zone myself, Sans," causing the skeleton to go rigid again.

Oh, this was truly going to be fun.


	13. Boning

**Summary for the Chapter:**

> Now that the entire setup is out of the way, time for the Reader to bang Sans! Caution for readers since I'm giving Sans a ghost vagina and the Reader a ghost dick.
> 
> Ninth kink: Role reversal with Sans on bottom and the Reader on top.

Two more months have passed since that day that you suddenly awoke with magical powers and were told that you are more monster than human now. Not only Sans, but Papyrus, Toriel, Undyne... All the monsters you've gotten close to have been helping you hone in your own powers of blue magic to manifest objects. At first, all you could summon were hands. Thanks to a certain lesson by Sans—which did not end the way he intended it—you quickly picked up on how to remain concentrated when using magic, and by now, you can summon up to six hands to do your bidding.

The next object you learned to manifest was a little different. This one had been purely accidental. One week night, you had been pleasuring yourself while your thoughts were with your loving skeleton. You imagined him doing things to you from usual caressing to more debauched acts, occasionally using one of your phantasmal hands to penetrate your other orifice which caused you to cry out into your pillow. You definitely did not need Toriel hearing you, after all.

Just as the pleasure was getting too strong to handle and you felt your peak coming, you squeezed your eyes shut and tried to imagine that your fingers was Sans' cock thrusting hard into you. It wasn't too hard for you to conjure such a thought. Skeletal hands on your hips as he grabbed them for leverage, hip bone colliding with your ass as he pounded into you, that thick, pulsating member that brought you to orgasm so many times...

It was then that you noticed something odd. Your right hand that had been pumping fingers into your wet pussy brushed against another object that sent a bolt of pleasure down your spine. Eyes snapping open in surprise, you sit up on your bed and find what you shouldn't have—a blue dick. One that looks quite similar to Sans', the only difference being that the one on your crotch seemed to be a little thinner in girth.

You hesitantly poked its tip wondering if you're imagining this... which you definitely are not. Just the simple brushing of fingers on its bulbous tip caused you to gasp. The sensation was similar to that of you prodding at your clitoris, though not as sharp or intense, and in no time, your gripped it like you would when lending a hand to Sans.

—The feeling was indescribable.

Similar to when you first learned how to masturbate, you shoved your face into your pillow and bit the fabric to suppress the loud moans that threatened to leave your mouth, your fingers frantically pumping the sensitive member in a tight fist. Even though your concentration waned at the powerful waves of pleasure, the phantasmal cock remained materialized. You could feel precum dripping everywhere onto your sheets, though you didn't give a damn at the moment. The only thought on your brain was the need to cum—for release.

When your fingertip accidentally brushed against a sensitive area on the underside of the tip, you cried out in abandon. You felt your hips jerk uncontrollably as your chest pushed into the bed while your ass thrust into the air. The feeling of liquid spilling out of the phantasmal dick was similar to when you'd take a piss, but the shivers running down your spine was much stronger than that.

As you came down from the peak, you rolled onto your side to avoid falling onto the spilled fluids. You laid there, heavily panting and just gazing upon what happened. Thick, blue cum stained your bed sheets; the ghostly member already gone. You relished the sensation of what a man must feel when he ejaculates and decided that cleaning up could wait until morning. Your final thoughts as you fell into a deep slumber was the excitement of showing your new trick to Sans this weekend.

 

* * *

 

 And now, you sat before Sans in his room. The skeleton frozen while sitting on the floor with his legs bent beneath him, his gaze locked on the blue member between your legs. Both of you are fully blushed—one bright red, while the other bright blue—and at a loss of words. Eventually though, you give a small cough and speak up in a tiny voice.

"U-U-Um... I-If you're not comfortable doing this... I-I don't mind, y-you know, being on bottom..."

Sans' face snaps up at that comment. "N-No, it's fine! I just, well..." he mumbles, "I-I never thought anyone would wanna try anything like that with me... You know... Me being a skeleton and all..." A wry smile creeps up on him as he continues on. "Seriously though, I still keep wondering what you see in a guy like me that you'd want to bone me. I'm lazy. I'm short. I'm not soft or cuddly like you are. I'm usually the butt end of someone's joke and—"

You had heard enough at that point and tackle hug him before kissing him. You rain kiss upon kiss on his teeth before clasping his cheekbones.

"Sans... I can't think of anyone else that I could love more than you. I said the same things to you that night your took my hand and kissed it... I'm short. I'm closer to a skeleton than human. I'm not pretty. But... you said that I was beautiful," you gently give another kiss while pausing a moment. "...You're perfect in my eyes, Sans. I... want you to know how you make me feel too."

Eyes going wide at your words, Sans' smile shifts from an awkward one to a more genuine smile. "...Thanks, kiddo," he says while nuzzling his forehead on yours.

A short yelp leaves you as Sans scoops you up into his arms and trots over to the bed to softly set you down on it. He moves some of his pillows so that you have something to lean against, all the while peppering you with kisses and running his hands over your body. Once he settles down between your legs, he gives his usual smirk.

"Welp, I better make this experience worth your while." With that comment, Sans' eye glows blue and he dips down to wrap his magical tongue around your member, causing you to gasp in surprise. "Like that...? I'm doin' what you always do for me," he says while continuing to drag the cold tongue against your ghostly dick, making sure to not leave any part of it untouched. Since he has no lips, he mainly concentrates on lapping at the pulsating member, but still occasionally grazing his teeth over the tip, the hard nips making you writhe underneath him.

Though Sans hasn't been pleasuring your phantasmal dick for that long, your breathing is labored and you have to stop him. "S-Sans, nnnh, s-stop...! I-I'm gonna cum if you k-keep that up...!"

Sans immediately stops his ministrations, though only after giving the seeping tip one last lick. "Heh, now that would be a sight to see. But you're right. Don't wanna wear you out bone-dry before the best part." He sits back to take in the rare sight of you trying to cover you blushing bright red face with your hands, body quivering as it teeters on the edge of orgasm, your knees tightly shut together as the throbbing dick jolts every time your pussy clenches. "Mm... I wouldn't mind doing this again if I get to see you like this every time. But enough talk."

You watch with trembling breaths as Sans takes off his clothes and chucks them off to the side. After he gets back on his knees to straddle your hips, his blue magic travels down from his eye to his spine, swirling around the pelvis and eventually settling around the sacrum to form... a phantasmal vagina? It looks similar to yours—for most likely obvious reasons—and you can't take your eyes off it as Sans expertly licks his fingers and massages the magical entrance with them.

Sans leans down to kiss you before he pulls back just a hair to whisper, "...Ready for the ride of your life?" He takes your fervent nod as the only answer he needed and returns to his straddling position again. "H-Hope you don't mind me going slow... Never done this with anyone, y' know?"

There's no argument from you on that. You reassuringly rub Sans' thick femur all the while watching intently as he lowers himself down on your dick, both of you unable to hold back the sharp gasps when the tip breaches the entrance.

Sans is tight— _gloriously_ tight—his quivering folds squeezing down on you every time he takes another inch, and then another inch of your length. By the time his hip bone comes in contact with yours, Sans' eyes are squeezed shut from the overwhelming sensation, his tongue hanging out from being unable to shut his jaw. Even though he is seated on you, you feel as if his heated pants still brush over your naked body.

A few minutes go by where you don't dare even move or twitch at all. You remember when it was your first time and how much it took for you to get used to a thick dick being inside you before you were ready for Sans to move. It's only when Sans finally opens his eyes and gives a small nod that you cautiously move your hips.

"O-Oh _fuck_!" Sans cries out, just from that one motion. His bones rattle as his entire body spasms, his hands fisted into balls on your stomach. "O-Ohhhh shit... Shit, shit, shit...!" All he can do is curse as you take his reaction as a good sign and continue rocking him on top of you.

"Nnnh... Oh Sans... Th-This feels so good..."

The skeleton atop you nods frantically, all the while trying to match your rhythm. You don't want to let your eyes leave him even for a moment because this is such a beautiful sigh—Sans, the one who always brings you so much pleasure, is writhing, panting, and bouncing up and down on your phantasmal dick in pure abandon. Your mind quickly becomes overtaken with lust and you reciprocate by grabbing his hip bone and slamming Sans down on you. Another sharp cry and a loud curse fills the small room as everything becomes a blur. Every rock of your hips, every tightening of Sans' inner walls, and even the sight of seeing your dick penetrating through Sans and brushing against his spine adds to the debauchery.

It doesn't take long before orgasm hits you both out of the blue. Sans cries out your name and his walls clench down on you like a vice, triggering your own scream of completion. Your hips buck wildly as spurt after spurt of thick, blue liquid bursts out from the hyper sensitive tip, the ooze covering the inside of Sans' rib cage. For a few seconds, neither of you dares to move, lest it triggers another unexpected peak, but once the waves of pleasure begins to subside, your phantasmal dick and his magical vagina disappears and Sans collapses onto your chest.

"F-Fuck... That... was amazing..." Sans whispers.

You give an exhausted giggle at his comment, since you remember those being the exact words you had said to Sans many months ago. "Yeah... That WAS amazing..." As tired as you are, you still move both your arms and hug your skeleton lover tight. "...Thank you. Now I know what it's like when you're fucking me."

"Heh... Glad to know what it's like being taken to the bone zone too," Sans snickers back, nuzzling your warm breasts. "Still prefer being the one boning you though." He shifts his body and puts his chin on your chest as he quietly asks, "...Mind having another skeleton in you later? As fucking amazing as that was, I gotta return the favor."

Another giggle leaves you as you lightly kiss his teeth.

"Of course. Anything for you, Sans."


	14. Submission (Part 1)

**Summary for the Chapter:**

> Thank you for the comments as always! I read every one of them and usually end up rolling around on my couch in happiness and embarrassment. There was an idea in the comments that struck a chord with me, so I changed up the idea just a little and ran with it! I had to split this chapter up into two parts though because this kink is taking longer to write.
> 
> Tenth kink: Master/slave pet play with a hint of porn watching

On most occasions when you were over at Sans' place on the weekends, Sans spent all of his time with you. Unfortunately, this one happened to be one of the few instances where he was called out to work for an emergency—the smaller skeleton now works at a local fast food restaurant, and one of their employees suddenly called in sick—and Sans reluctantly left you to have some alone time.

For some time, you rolled around on Sans' bed, reading some posts online on your cell, looking up new recipes to try out, taking a quick nap... but even after you woke up, Sans was still not back yet.

After giving a small yawn, you looked around and your eyes settled on the computer in the room. Sans had mentioned that you were free to use it if you were bored, so you decided to check it out. Now that you think back on it, that should've been a sign that the skeleton monster was up to something, though at the time, you wouldn't have even given it a hint of a thought.

* * *

The computer in Sans' room is no different from the one you use at Toriel's place. It takes a few minutes to fully boot up, but once it does, you open up the internet browser and begin looking up the usual sites you check on. Though you had been browsing the internet on your cell phone earlier, there is a limit to the things you can check on it. The light clicking of the keyboard as you type in different addresses echo across the room, and after a number of websites later, you notice something.

On the browser's bookmarks bar is a folder that is labeled as "Weekend Ideas." You hesitate clicking on it for moment since this is Sans' computer, and intruding on his privacy seemed as though you were over stepping your bounds. Still at the same time, the mischievous side of you wonders what could be in those bookmarks. Could it be Sans checking out local places to go to? Or perhaps he was browsing forums to get ideas on what to do when you came over on the weekends?

Curiosity wins in the end, and you click on that folder. Over twenty or so links that are all unnamed appear, which is slightly odd since other bookmarks in the bookmark bar were named properly, but you just shrug it off and click on the first link.

The website that loads is a simple one with a black background and a single video embedded in it. No banners, no other links... Deciding that the simplicity must be because this is someone's personal website, you click on the video and turn on the small speakers that are plugged into the computer itself. However, what loads is not what you were expecting.

The video begins with a woman in a simple, black dress appearing on it. Her face is flushed and seems to be in some kind of discomfort as her body trembles and her knees are shut tight together. Then, there is a voice. A deep, man's voice who addresses the woman by name, and that is all. Seemingly understanding what the man wants, she meekly nods and begins stripping her dress off.

Your mind freezes at that exact moment, finally putting one plus one together in that this video is a porno. You wonder why Sans had bookmarked this particular video under "Weekend Ideas," but you are determined to find out why.

As the video continues to play, the woman has cast off her dress to reveal that she isn't wearing any underwear. The only thing you can see is some kind of cord coming out from her crotch that is attached to a controller strapped to her leg—when it hits you that it's a vibrator inserted into her vagina, your face blushes bright red. The same man's voice is heard again as he orders her to get on her knees. She shyly complies, all the while keeping both her hands on her thighs.

That is when the man comes into the video's frame and gently caresses the woman's cheek, only to bring up what looks like a collar and carefully puts it around her neck. The woman is complacent throughout this action, even canting her head up and offering her neck to make it easier for the man to adjust the strap around it. Once the collar is in place, the man steps back and examines it with a smile.

["You've been quite a good girl, isn't that right, my dear pet?"]

Pet? Did he just call her pet?

As the man gently pets the woman's hair, she responds in a breathy manner. ["Yes, master."]

["Well done. Now, on the floor, pet. Show yourself to me."]

Another breathy, "Yes, master," is returned as the woman turns around while still on her knees. She then bends over onto her hands, then elbows, and finally onto her head, yet remembering to keep her legs spread and ass in the air. The man gives an approving nod, just watching and doing nothing at the moment. Still, things quickly escalate when the man takes out what looks to be a small whip and gives the woman's bare buttocks a light slap with it. The woman whimpers at the sharp pain, but bites back any other noise from falling from her mouth.

Your eyes are glued to the screen as you continue watching the man give a few more light whips to the woman. You've heard of pet play and master-slave play before, though you never actively sought out such a kink online. Why Sans has this video bookmarked is beyond your knowledge. That doesn't stop you from wondering what it would be like if he was the one doing such an act on you.

As the man in the video eventually kneels down and begins fingering the now dripping wet woman, you can't help the small whine that leaves your lips. Your legs have instinctively shut and your knees are uncomfortably rubbing together in obvious need. When the man slowly tugs the vibrator lodged within the woman's vagina out and the woman cries out, ["P-Please let me cum, master!"] the man gives his approval. The woman orgasms hard, from what you can tell, and as her pussy lips spasm and ass jerks in the air, she mutters a heated, ["Th-Thank you, master..."] before the video ends.

You take a quick look behind you and listen to make sure that Sans hasn't come back yet. Once you've made sure that the only noise you can hear is your own heartbeat thundering in your ears, you click on the next bookmark in the folder.

Just as imagined, a similar looking website loads with one video again. You immediately click on the new video, which turns out to be continuation from the previous one. The same woman is in this video as well, though this time, she is laying on a bed with her fingers slowly tracing her pussy. A man's voice is telling her what to do, and when it seems that she is getting close to reaching orgasm, the man commands her to stop, causing the woman to plead to keep going. Though you don't notice it, that is about when your fingers begin wandering down and you begin touching yourself.

What would it be like if you were in the situation and Sans was commanding you to do this? You'd happily oblige for one, but how long would you be able to obey his orders of keeping yourself on the brink of orgasm?

Your fingers are applying pressure on your clitoris from above your jeans, but the sensation is not enough. After one more quick glance behind you, your jeans are cast off and fingers slip under your panties to directly touch your already wet pussy. Watching porn always got you hot quickly, after all, since you'd imagine yourself being the one receiving the actions on video from Sans. However, what's making you feel more turned on than usual is the fact that you're in Sans' room, watching something that Sans himself must've bookmarked to get new ideas to try out on you, and that Sans could come home at any moment. Still, you can't stop yourself from touching your moist nether regions.

In your mind, you imagine that the one commanding you is Sans. You listen to the words coming from the video and only move your fingers according to what is being said. It's already been established that Sans like showing dominance in bed, so you can easily imagine him saying these dirty words to you. He'd tell you to continue fingering your pussy, only allowing you to insert just the tip of your middle finger so that the frustration leaves you wanting more.

When that video ends, you hurriedly click on the next bookmark. And then the next. With each video, your breathing becomes labored and hot, and you can feel your fingers completely covered and slick with your own juices.

The last link you've opened up has the woman now back on her knees with the man standing fully clothed before her. She's frantically touching herself—stopping them once in a while so that she doesn't cum without her master's approval—as she unzips the man's fly with her teeth. She then tugs the pants down in a similar manner, following that with pulling down the man's underwear so that his throbbing penis could be freed. The woman whimpers and is about to lick the towering member, but that is when the man steps away. Pleads fall from the woman's mouth in want of pleasuring the man, to allow her to please him with her mouth.

You can feel your mouth go dry at that scene. Your middle finger is lightly caressing the inner walls of your pussy while you swallow hard. If Sans were to pull something like this on you, you'd be a begging mess as well. You would want to beg him to allow you to suck him off, to let you wrap your lips around his thick member just so you can please him. More heated pants fall from your lips as the man is just about to allow his pet to perform oral on him, when a hand is suddenly placed on your shoulder.

Your body jolts in surprise and shock as a familiar face rests on your other shoulder. "...Looks fun, doesn't it? Thought you'd be interested in giving this a try."

Sans. His smirking reflection is on the computer monitor. Your lover has returned, and has now caught you watching the porn he had bookmarked. Your heart is pounding so hard that it feels like it's about to burst. Whether Sans senses your panic or not, he continues to keep his eyes on the screen and whispers into your ear.

"You've got such a lovely neck... Don't you think a collar like that would look nice on you too? Would you want me to call you pet as I tell you every action I want you to perform for me...?"

A strangled whimper leaves your mouth, but you give a small nod in return. You love Sans being dominant in bed, so taking that dominance a step further would be utter bliss for you.

"Good..." Sans whispers again, clicking the pause button on the video and closing the browser. He spins the chair you're sitting on around so that you're facing him. Sans' left eye is already blazing blue and a familiar bulge can be seen on his crotch as he stands before you. "Well then, on your knees, _pet_ ," he practically purrs, and you couldn't be happier to comply.


	15. Submission (Part 2)

**Summary for the Chapter:**

> And here comes part two! The master/slave pet play continues on! I have to agree with some of the comments I received on the last chapter though. If I was ever caught in that situation, I'd probably scream and run out of the room, an embarrassed mess. I'd probably end up locking myself up in the bathroom from utter shame, haha.
> 
> By the by, I'm really bad with coming up with puns, so my Sans is severely lacking in puns... I hope no one minds it!

Of all the things that could ever happen, you getting caught watching porn on your lover's computer was definitely not on your list. But that was what happened only a few moments ago, and both anticipation and hesitation fills your heart as you quickly slip off of Sans' chair and obediently kneel before him.

Sans gently runs the back of his hand on your flushed cheek, to which you happily nuzzle into. Seemingly pleased by your reaction, Sans pulls something out from behind his back. "Good pet... Now, we can't kick this off without getting into character, no?"

A small smile tugs your lips when you see what he's holding: a black, leather collar, just like the one you saw in that porno. As you attempt to remember all the things that happened in those videos, you keep your mouth shut while canting your head up a few degrees, allowing Sans access to your neck. You attempt at staying calm as Sans smirks and begins putting the collar around your neck, but the feeling of the hard leather against your skin makes your breathing ragged and hands tremble in anticipation of what's to come.

"There we go. Yep, just as I thought. This collar looks great on you."

Sans' comment makes you smile even brighter. Although, he seems to be waiting for something more than just your happy expression... Oh. That's when it hits you on what Sans is waiting for.

"...Th-Thank you, m-master," you mumble out, the words feeling foreign on your tongue. It didn't come out as smooth as you liked, but thankfully Sans doesn't seem to mind your stutter, if you're reading his grin correctly.

"That's a good girl. I knew you'd be a fast learner," says Sans while he cups your jaw with one hand and traces a bony thumb over your lips. "I like obedient pets... Now, keep your hands behind your back and open wide."

The heat that had been lingering in your crotch bursts aflame at those words. You can easily imagine what Sans has planned for you and you immediately do as he says. Once your hands are placed behind your back, there is a cool sensation brushing against your wrists: Sans has summoned two of his phantasmal hands to grip them, to make sure you don't go against his word. A small shiver runs down your spine at that feeling, but you try and stay focused. Finally, you open your mouth wide just as Sans commanded you.

Sans gives an appreciative hum at that sight. The thumb that was caressing your lip dips in and rubs against your moist tongue, only pulling out after you've traced every groove of those bones with it. Once the bony finger leaves your mouth, the skeleton monster takes a half-step back and begins tugging his pants down. Immediately, his blue, thick cock springs out, making your mouth water at that sight.

There is a part of you that wants to lean forward and suck on that throbbing member, but you fight that urge. Sans hasn't commanded you to do so yet, and you can only imagine what he will do if you disobey him. However, just that sight of that blue member is enough to get you riled up. You continue to gaze upon it longingly with your mouth hanging open.

By now, you've memorized every inch of it from its bulbous head to its slightly bulging length. Seeing precum seep out and slowly trickle down the shaft makes you whimper. You want to please Sans so much that you can't stop the increasing pants from leaving your mouth.

When Sans finally takes that half-step forward again, he locks eyes with you. "Good... Eyes on me while you suck me off, pet," he says while gently slapping his phantasmal dick on your cheek.

Oh, you're more than happy to oblige.

...But as you pepper kisses to the seeping member and are about to begin licking it, Sans suddenly stops you with a gentle tug of your hair. You wonder if you've done something wrong.

Sensing your worry, Sans gives a smile. "You've been obedient so far. It's only fair that I throw a bone to you too, so that you're not feeling bone-ly." With those words, there is a snap of fingers and suddenly one phantasmal hand rips your soaking wet panties off you to cast them off to the side, while another spreads your puffed up pussy lips.

You can feel more juices seeping out and trickling down your thighs, but what causes you to snap your vision down is the cool, yet familiar object being pushed against your pussy. Another blue dick has formed on the ground between your legs—one that is much longer than the one near your face, and is slowly increasing in length until it breaches your aching entrance.

"A-Aaah...! M-Master...!?" you manage to moan out, the insertion of the second member making it hard for you to maintain your kneeling position.

"Mm... There. Now I can enjoy your mouth and your pussy at the same time," Sans sighs. "Well, get back to business, pet."

It's definitely harder to concentrate now that there is a thick cock slowly pumping in and out of you, though that doesn't break your determination. You resume what you had been doing until Sans stopped you, starting with licking the entirety of the cock from the base to its tip, and then taking that tip into your mouth. While gently suckling on the bulbous tip, you enjoy listening to Sans moan appreciatively, making sure to swirl your tongue against the sensitive underside which causes the whole member to jump.

"Oh, fuck yeah... That's good... Keep going," you hear from above as Sans' eyes narrows dangerously. That look sends another shiver down your spine, and that combined with the thrusts of the cock under you is teetering you faster to orgasm than you'd like.

You step up your game and fully lick the phantasmal dick before taking its length into your mouth. Fully deep throating him isn't going to happen since your gag reflex isn't trained that well, but you still take in as much of Sans' length as possible, sucking on the pulsating member while at it. You lick, suck, tease, and pleasure the slightly cold rod to the best of your ability. And not too long later, you see Sans give a growl and take hold of your head.

"Fuuuck... Nnngh, you're mouth's too good, pet...! Keep sucking like the good slut that you are...!"

Sans begins thrusting his hip into your face, going only so far that the tip rubs against the roof of your mouth and the act doesn't cause you to gag. The member slipping in and out of you also begins moving faster—at the exact same pace as the one fucking your mouth, for that matter—making you whimper in need. Yes, the feeling of being spit roasted by Sans is absolutely divine, yet you desperately fight back the urge to cum all because Sans hasn't given the order for you to do so yet.

Your hands being held by phantasmal ones tighten into fists. Rapid, shallow breaths through your nose mixes in with the whines coming from your throat as Sans continues to fuck you from above and below.

"Nnh, oh yeah, I'm gonna cum...!" moans Sans as he pulls his dick out of your mouth and continues to pump it with his hand. "C-C'mon, pet. Open wide...! I'm gonna give you my hot, sticky cum...!" Seeing that he is going to cum any second now, you open your mouth wide in anticipation, your cheeks flushing an even brighter shade of red.

Not a second later, Sans' body jerks and he lets out a cry as he releases his load onto your face. Another whimper leaves you as bursts of hot, blue cum spurts out from the tip. Some lands on your face, while the rest of it is intentionally poured into your mouth by Sans; the sticky, sweet taste and smell that you know too well makes you feel dizzy.

"O-Ohhh... Good girl... Yeah, keep that mouth open... Lemme see my cum in your mouth..." whispers Sans, as he leans over and kisses your forehead. "Do you like that, pet? You want to swallow my load so much, don't you?"

You give small, frantic nods at his question.

"Well, you have been obedient..." Sans kneels down to match your eye level. He runs bony fingers across your pussy lips that are still tightly squeezing on the other blue member, kneading the engorged clitoris with his thumb before continuing on. "Cum for me, and then you can swallow. Can you do that? Hm?"

Just that thought alone almost tips you over the edge, but it wasn't enough. Your return of a heated nod satisfies Sans, and he gently cups your jaw to close your mouth, but keeping his gaze sharp to prevent you from swallowing. As soon as everything is ready, the dick under you begins to thrust hard into you.

Your eyes begin to water as the pleasure starts to become too much for you: the smell of Sans' cum still on your face, the taste of it in your mouth as it sloshes around, and the wonderful sensation of the thick member pounding into you... And the way Sans is looking at you. Dear lord, the look of blazing lust as you moan through closed lips mixed in with everything else is utterly intoxicating.

"C'mon... Just let go. You're already so close," purrs Sans. Fingers pinch your hard, sensitive nipples from over your shirt to aid you in attaining your peak. "Cum for me. Cum for your master... my dear... lovely... slutty pet."

It's that tone of voice that tips the scale. Tears pour down your cheeks as your eyes shut tight and orgasm wrecks your entire body. Your knees give out as you accidentally fall onto the hard cock, the tip jamming right at your sensitive cervix triggering another orgasm immediately after your first one. You want to gasp. You want to scream Sans' name, but you can't. Your body continues to jerk and tremble as you feel Sans cup both hands around your face to tilt it up.

He smiles lovingly before whispering, "Swallow."

You do, and another orgasm hits you just like that. There is a slight look of surprise on Sans' face as orgasm after orgasm continues to hit you with each swallow, but the surprise melts back into a gentle smile. He tenderly runs his skeletal fingers through your hair and whispers loving words, only to catch your collapsing body when all strength finally drains from you. A strangled whine leaves your throat as the phantasmal member on the ground disappears and Sans scoops you up into his arms. He carries you back to his bed, gently putting you down on it.

Once your vision clears and your breathing returns back to normal, you give a weak smile to Sans. "Did... I do a good job...?"

"More than a good job, kiddo. That was one of the hottest things you've ever done for me."

A small giggle leaves your mouth at Sans' phrasing. You close your eyes as your skeleton lover pulls out some tissues and wipes off the blue cum that is still on your face. Even though you enjoyed this master and pet play very much, there is still one thing you're curious about... "Hey, Sans...?"

"Mm?"

"...Did you know that I'd look through those bookmarks?"

Sans smirks at that question. "Well... I sure hoped you would. Still, I didn't think I'd find you touching yourself like that. Good thing I decided to keep this collar with me, just in case you were in the mood."

You bring your hand up to your neck and touch the leather collar that's there. It seems you've been set up by your lover, though you can't bring yourself to be upset about it. The fact that Sans took the time to set all this up, just so you two could add another level of spice to your love life is touching for you.

"Anyway... I bet you must be hungry after all that bone-licking goodness. I bought some food for us, so lemme go get it."

You return a nod at Sans' offer. But before he can leave, you tug on his jacket to get his attention.

"What's up, kiddo? Do you need something else?"

A small shake of your head. Your cheeks heat up once more as you whisper to Sans, "...Can we play some more after lunch?"

Your words trigger a bright blue blush to appear on Sans' cheeks. He quickly shakes it off though before leaning down to kiss you once more, all the while muttering, "...Seriously, kiddo. You're too good to me." Sans ruffles your hair and tells you of course, and then disappears from the room.

While Sans is headed downstairs to grab the lunch he brought back, you smile and close your eyes. You can only imagine what Sans will dish out for you later, but determination burns bright within you. Perhaps he'll even let you play the role of master sometime as well... and that thought makes you smile even wider.

Another kink crossed off the list, while there would be more to come.


	16. Gazing

**Summary for the Chapter:**

> I know I say this every chapter, but thank you everyone for leaving such nice comments...! I never thought I'd write a fic that got so many reactions! This was a random idea that popped in my head while showering, so I decided to do a short chapter with it. (I'll be taking into consideration some of the ideas that people have been kindly leaving in the comments.)
> 
> Eleventh kink: Sans shaving your nether regions while taking a bath with him

You swear that you must've angered some kind of weather god in whatever past life you may have had. For the umpteenth time, the day's weather quickly plummeted south as what had been a bright and sunny day suddenly shifted to ominous looking dark clouds, eventually leading to heavy rain pour while on your way to the skeleton brothers' house. Just like that day when you arrived at their place shivering and covered in snow, you now stood at their doorway drenched in water.

When Sans and Papyrus greeted you, you could tell that the smaller skeleton was going to make some kind of inappropriate comment. There was that certain gleam in his eyes. His smirk was a few degrees more canted up than usual. Before you could stop him, he snickers out, "Wow, I know that you're always up for jumping my bones, but you didn't have to come literally soaking wet like that."

"SANS!"

"Sorry, couldn't help it," Sans laughed back, obviously unapologetic.

Thankfully the sexual comment went over Papyrus' head—bless this innocent and pure cinnamon roll—and he reprimanded his brother for making fun of your state. Papyrus gave you a quick wipe down with the fluffy towel on the coat rack inside before ushering you and Sans upstairs to take a bath. According to the taller skeleton, Sans had been lazy and hadn't been showering as of late. And since you're the only person that he'd happily take a bath with, Papyrus asked you to take care of his brother.

Seeing no reason to turn down his request, you nodded and headed upstairs towards the bathroom while holding Sans' hand.

 

* * *

 

The skeleton brothers' bathroom always amazes you. It's always stocked with amenities, freshly washed towels, and other essentials, but what you enjoy the most about it is the large bathtub. You've enjoyed it with Sans multiple times by now and it's always spacious enough to fit more people if needed. In any case, that needs to be filled first.

You twist the metal nob and test the temperature of the water pouring out. Once satisfied with its warmth, you place the plug into the drain hole, allowing the tub to fill. A few small scoops of your favorite bath salt later, you feel a weight on your back.

"Sans?" you ask, as two hands gently spin you around so that you're facing the skeleton monster.

"C'mon. Lemme help you get out of those drenched clothes. Don't want you catching a cold."

"Thanks," you smile back, allowing Sans to undress you. He first pulls off the wet jacket and your shirt, then moving down to pull off your jeans, which happens to be harder than it looks since the material is sticking to your skin. For a moment, Sans hugs you before unhooking your bra and putting it off to the side. It's only when he kneels down and slips off your panties that he stops.

You notice him staring at your... nether regions? "Hm...? What's wrong, Sans?"

Sans curiously brings up one hand, a skeletal finger twirling your pubic hair. "Huh. Never seen this before. Did this grow?"

Your cheeks heat up a bit at the inquisitive comment and how he's staring with such curiosity at your pubes. A clearing of your throat, and you answer back, "U-Um, yeah... S-Sorry, I usually shave it off because it gets itchy... H-Heh, must be weird, huh? This sort of stuff just keeps growing back on humans."

The pair of eyes continues to stare and play with the small bush until Sans looks up at you with a bright smile.

Oh no... You know that look.

"Can I shave it off for you?" he asks with a twinkle in his eyes. "Gotta admit, this body hair stuff makes me curious." However, seeing that you've frozen and your face is turning brighter red by the second, Sans gives you his best puppy dog eyes and asks, "...Please?"

...Who are you kidding? There's no way you could say no to such a face. You mumble an embarrassed, "Okay," wondering what you've gotten yourself into.

 

* * *

 

Once the bath tub is fully filled and both you and Sans soak in it for a few minutes, Sans makes sure that you've warmed up before helping you sit on the edge of the tub. He hums a happy tune while grabbing a disposable razor from the amenities stash—why there are razors in this house eludes you, considering that neither Sans nor Papyrus needs to shave—and the bottle of soap.

"Don't worry, I've seen how all this works online. I was hoping I'd get to try it out myself some day," says Sans as he froths up the soap in his hands. "Alright, spread them, kiddo."

You wish you could bury your face in your hands as you spread your knees apart, allowing Sans complete access to your crotch. The soap being applied is warm, adding to the warmth of your body heating up from embarrassment. You've never had Sans take such a close look at your crotch before, and though it isn't making you uneasy, this whole situation is a bit... turning you on.

The bathroom goes rather quiet, save for Sans' small humming, the dripping of water, and the sound of the razor carefully shaving away your pubic hair. Each time the razor comes into contact with your skin, you have to keep yourself from jolting at the ticklish sensation. Never did you think that someone else would be doing this.

Slowly, the small patch of hair disappears. Though Sans must not be doing it intentionally, the way that he carefully moves the folds of your vagina to not miss any stray hairs is causing shivers down your spine. The light touches and the concentrated gaze only make it worse for you.

"And there. That should do it," Sans eventually says while pouring some warm water on your crotch and wiping away the remaining soap. "I was worried that I'd accidentally nick you with the razor, but it wasn't too... hm?" The skeleton's voice trails off.

...Crap, you think in your head, as a curious finger trails up from the bottom of your pussy to the now engorged clitoris. You can practically see the mischievous glee rear its head in Sans as he looks up at you from between your legs at the slick sensation on his fingertip, but before you can utter anything, a hint of blue lights up the walls and a sharp cry leaves your lips.

—Sans had quickly nestled his face in your crotch and lapped the moist lips with his thick tongue.

Your hands shoot up to cover your mouth as he continues to run the cold tongue at a languid pace from the bottom of the folds, making sure to apply harder pressure when he reaches your clit. As much as you'd like to enjoy Sans eagerly eating you out, Papyrus is still downstairs. You can't afford making any loud noises that could possibly draw his attention.

But Sans is good. Too good. The way that he makes certain to leave no part of your pussy untouched, the way he laves the skin around it that's sensitive from the shave, and how he dips in the tip of his tongue from time to time into you is driving you wild.

Small whines escape from closed lips while your breathing becomes heavier through your nose. You're getting close to cumming as your legs unconsciously squeeze down on Sans' skull, that movement adding further encouragement and eagerness to his ministrations. Just one more hard thrust of his tongue into you is enough to push you over the—

"Sans, human? Are you two still in there?"

Your body freezes as a knock comes from the bathroom door, along with Papyrus' hushed voice. The need to cum is powerful, yet the fact that Papyrus is but a wooden door away from you causes you to frantically look down and shake your head towards Sans. However, such a reaction encouraged the skeleton monster only further and he thrusts his long tongue harshly into you, causing your peak.

You see stars behind your eyes as orgasm hits you like a ton of bricks, and a heavy moan almost leaves you, had it not been for Sans pulling his tongue out and covering your mouth with his own hand as well. While your mind is in a haze at the powerful orgasm, you vaguely hear Sans talking to Papyrus.

"Sorry, bro. Looks like I'm taking longer to clean up."

"Oh... Okay! Is the human making sure that you're fully washed up?"

"Yeah, she's giving me quite the scrubbing here. We'll be out in a bit, Pap."

"Very well! The Great Papyrus shall make sure that dinner will remain hot until you two get back downstairs!"

And like that, you hear Papyrus rush off. Once his heavy footsteps echo through the house as he heads down the stairs, Sans looks back up towards you with a smirk. "Aww, whose my pouting little kitten?" he teases, all the while pulling you back down into the warm water.

You indeed give him a blushing pout and lightly slap his skull, which only causes him to snicker more and hug you tight. "Sans..." you say in an exasperated manner.

"Yep, that's my name."

"Seriously, Sans!"

"Heh, couldn't help it," Sans shrugs while nuzzling into your shoulder. "Had to get a good taste of you when you're dripping wet for me like that."

You give a half-hearted sigh once more before submersing yourself deeper into the water. Sans can tell from your mood that you're not mad at him and he chuckles again. You can't deny the fact that what he did was quite nice... though it would be nice if you can get back at him for once.

That's when a thought pops in your mind. A sly smile appears on your face as you remember the conversation from a moment ago. Sans had told Papyrus that you were giving him a good scrubbing of his bones...

"Hey, Sans?" you ask while turning to him with a sweet smile.

"...I don't like that look you're giving me, but yeah?"

You reach for the bottle of soap Sans had used earlier, all the while maintaining that mischievous smile. "You did tell Papyrus that you're getting cleaned... You don't want him finding out that I didn't give you that proper cleansing, right?"

"K-Kiddo, d-don't tell me you're gonna—"

All you return to Sans is a big smile, and pump tons of soap into your hand.

 

* * *

 

15 minutes later, you and Sans are back downstairs happily munching on Papyrus' homemade spaghetti—well, you're happily feasting while Sans' face is completely flushed blue and whimpering up a storm. Papyrus is quite confused as to his brother's antics, but he lets it slide as him being odd as usual.


	17. Scrubbing

**Summary for the Chapter:**

> I have a few more chapters planned out already, but considering the number of people who wanted to find out what exactly happened to Sans in the previous chapter, I decided to pump this out first instead. I considered writing this in Sans' POV, but trying to dodge around not using the reader's name proved to be difficult, so I'm still keeping this chapter in the POV of the reader. This is a quick one for the crowd!
> 
> Thank you for all the comments as always and please enjoy!

"C-C'mon, kiddo! I-I'm pretty much clean from just taking this bath! You don't have to go so far and—AAAAAAHHHHHHH!!"

Even if you wanted to, you couldn't have held back the giant smile on your face. The moment you grabbed at Sans with frothed up soap, the skeleton monster gave the most undignified yelp. You can't help but giggle along as your slick hands carefully lather the foam on Sans' rib, using a little more force with your thumbs to get off the grime you feel on them.

"Seriously, Sans. You need to wash yourself better," you chastise him while scrubbing even harder, causing more reactions out of him. The whimpers you hear are like music to your ears; each brush of your fingertips, each gripping and pumping of Sans' vertebral column causes the blush on his face to get stronger by the second. A number of times, Sans tries to say something and weakly grips your hand, though that doesn't deter your determination and a few more pumps of your hands caused him to melt into a puddle of goo.

Since his torso is now clean, you then move up to his sternum to both his clavicles, making sure to lightly scrape your nails on the hard bone to get some splatters of ketchup off on his humerus. "Really? Ketchup?" A couple harder scrubs and more whines. "How in the world did you get ketchup here?" you say while applying more soap on your hands and straddling Sans' lap.

"K-Kiddo, please...!" Sans pleads, his right eye flickering blue and yellow, obviously fighting the urge to let his magic go. Still, you're having none of it.

You give another smile as you pull the plug in the bathtub, letting the warm water drain before strongly gripping his pelvic bone. You know that this is his most sensitive area, and you're planning on exploiting it as much as possible. Of course, Sans tried to fight the wonderful sensations, but in the end, he couldn't help groans from leaving his clenched teeth.

First, you start by making sure you're up close to Sans as much as possible, letting your small breasts come in contact with his ribs. The feeling of hard bone against your nipples does turn you on a little, though thanks to Sans getting you off earlier, the pleasant sensation is quite easy to ignore. You then begin firmly scrubbing the pelvic bone all the while keeping eye contact with Sans. It's rare to see him this flustered, let alone such a whimpering mess under you. Had this been any other situation, you know that Sans would've jumped you by now.

Once your soapy fingers move further down towards his sacrum and eventually to the coccyx is when Sans loses it. His bit back moans turn into breathy gasps, head lulling back to the bathtub's ledge from being unable to handle the soft touches any further. You especially make sure to clean the coccyx with extra care since his phantasmal cock forms around here, and you can only imagine the grime that could be accumulated there.

As much as you're having fun here, you couldn't possibly make Papyrus wait any longer. You grab the shower and rinse Sans off before sitting back and smiling. There is a hint of hope in his eyes as you do so, but your smile quickly transforms into a mischievous one and you quickly toss a towel towards him. The hope in Sans' eyes immediately turn into panic as he figured out what you're up to.

"C'mon, Sans. We should get back downstairs. Don't want dinner getting cold, you know?"

"B-B-But, but...!"

"Better hurry or I'm gonna start eating without you!" you tease as you quickly jump out of the bathtub and wear the bathrobe that had been prepared for you. After slipping into a pair of fluffy slippers, you make your way out of the bathroom, only waiting long enough for Sans to come out fully dressed in a T-shirt and pants, breathing still heavy and face flushed blue. You make sure to take his hand and lead him back downstairs so that he couldn't run off to his room for some quick release, Papyrus obviously curious as to what's up with his brother, though not questioning it.

Oh, you know that you're going to pay for this later after dinner, but at the moment, seeing Sans a whimpering mess while slowly eating his plate of spaghetti was definitely worth the price.


	18. Long-distance

**Summary for the Chapter:**

> I'm sorry about the delay on updating this story! My brain's been fixated on another fic I'm working on, but since it decided to hit a writer's block, I'm pumping this chapter out first. As always, thank you so much for everyone leaving comments and kudos on this story...!!
> 
> Twelvth kink: telephone sex

Being the human that helped destroy the barrier between the monster world and the human one came with some unexpected tasks for you. Since you've been designated as the envoy to help fill in the gap between humans and monsters, you are flown out of state once a month to meet with senators, and even the president on some occasions, to assist the acclamation of monsters into the human society. So far, those trips have proved fruitful and it was thanks to having understanding officials that the school for monsters was built.

Unfortunately, this also meant that you were separated from your friends, family, and most importantly Sans during those trips. Only a few days appart from them seemed like an eternity for you. To make matters worse, the government had taken into consideration of working at the monster's school and set your trip this time to happen over the weekend, the time that you would've spent over at the skeleton brothers' house.

After the long meetings with government officials, you finally return to your hotel room and immediately fall face first onto the bed. Everything had gone smoothly with no hitches, but being in a place foreign to you and speaking with so many adults has drained your energy. You want nothing more than to skip taking a shower and just go to sleep.

You roll over onto your back and kick off your shoes at the very least. There isn't even any effort when you use your magic to summon a phantasmal hand to flick off the lights—it's quite useful when you're feeling this tired or lazy. However, before you bury yourself under the sheets and blankets, you stop and think for a moment.

Had this been any other weekend, you would've been spending time with Sans... Suddenly, you're feeling homesick and grab your cellphone. The time shows 01:03 AM, making you feel a little guilty of calling at such an hour, but you go through the favorites of your contacts list, quickly tapping on Sans' picture. You put the phone to your ear and close your eyes as the familiar ringing tone repeats.

A few seconds later, the voice you wanted to hear answers. ["...Kiddo? You're not butt dialing me, are you?"]

"Hey, Sans..." you answer with a smile, shifting onto your side to make it easier to talk to him. "Sorry, did I wake you up?"

["Nah, you know me. I rarely sleep before three on weekends, if you get what I mean."]

You can't help but blush a little at his comment. True, weekend nights usually end up extending late into the night because you and Sans tend to be... getting it on, in layman's terms.

"Sans, if you were here right now, I'd smack you for that," you giggle back. You pause for a second, before holding the phone closer to you and whisper, "...I wish you were here."

["...Me too, kiddo. Too bad you weren't closer 'cause I would've been waiting in your hotel room when you got back."]

"Haha! You would've totally freaked me out!"

You hear an equally amused chuckle from the phone, and from there, the two of you begin conversing about the things that happened during the day. Topics range anywhere from the meetings you had today to the special ketchup Grillby has started serving at his new restaurant. To be honest, it doesn't matter what you're chatting about. Being able to hear Sans' voice is all you need to get rid of the home sickness you were feeling.

Few minutes later, Sans goes quiet for a moment. Since the conversation suddenly cut off, you wonder if you accidentally cancelled the call. However, your phone does show that it's still connected...

"Sans? Are you still there?"

["...Yeah. Hey, I know it's late... but you got time?"]

"Of course. What's up?" A hint of worry seeps into your voice at Sans' tone. You sit up on your bed and re-adjust the phone on your ear. "Is something the matter?"

["Oh, nah, it's nothing like that,"] Sans responds. You internally sigh in relief, though that relief quickly turns into something else when he continues on. ["...You have no idea how much hearing your voice is making me hard."]

Your breathing hitches at that hushed comment, Sans' tone switching from his casual, lazy voice to one that is guttural. Just those words sends a shiver down your spine, along with a warmth that is quickly spreading in your loins. Your knees immediately lock together, though that isn't enough to quell the longing you feel.

Your heartbeat kicks up a notch as you hear Sans give a breathy sigh. The small shuffling of cloth in the background can only mean one thing. You clear your throat before answering, "...Mind telling me how hard you are?"

["Only if you tell me what you're wearing right now,"] Sans teases back.

Now you know exactly what game he's playing at. (Well, two can play at that game...) you think, as you shimmy out of your jeans and toss them to the floor. There is a loud gulp on the other side of the phone, and you laugh internally at how bright blue Sans must be right now.

"Well... I was about to go to bed, so all I'm wearing is a T-shirt and panties right now," you whisper back, getting yourself comfortable since you know where this is going. "So... are you touching yourself?"

["Can't leave myself bone-dry, right? Nnh... Never knew I could get this rock hard."]

The faint, but still labored breaths coupled with his words makes you sigh and close your eyes, easily imagining that familiar bulge that must be formed under Sans' pants as he lazily strokes it. "Oh yeah...? Mm, I guess you can imagine what's going down in my nether areas then..." you reply while bringing one hand down lower and lightly tracing your crotch with two fingers. It doesn't surprise you that your panties are already wet.

["I bet you're dripping wet... Shit, if only I could be there right now to lap it all up."]

That imagery strikes a nerve and a strangled moan leaves your throat. Sans has proved time and time again that he's amazing at giving head, every instance in which he pleasured you with his tongue burned into your memory. That thick, blue tongue and how it would roughly lap your folds...

You can't take it any longer, chucking your panties off and quickly begin rubbing your sensitive clit.

["Ohhh, I can hear that, kiddo... You're not just dripping wet, you're fucking soaked...!"]

"Nnh, wh-what can I say...? Just imagining you doing things to me is, ahh... is making me burn up."

After making sure to move your fingers so Sans can hear more of the wet noises, you slow your pace down. While teasingly using your fingertip to massage the entrance, you re-adjust the phone before continuing on. "If I could be there right now... you know what I'd want to do...?"

["Dear god, tell me in detail. Don't leave me hangin' dry here..."]

"Mm, I'd probably start by licking that bulge over your pants... Nuzzle it a bit, suck its tip, let it ooze pre-cum out from under the cloth..." You pause a moment to lick your dry lips, the noise unintentionally triggering a strangled moan from Sans. "I know you'd get impatient. I bet you're scrambling out of those pants right now... You just want me to take that thick... dripping... cock in my mouth... don't you?"

["Fuck yes!"] he groans back, audibly slick noises accompanying his curses. ["I'd shove my dick in your hot mouth, nngh, m-make you suck me so you can get it all wet... You wouldn't need any prep work, w-would you? You'd have your fingers knuckle deep in you as you're sucking me off."]

You bite your lip at his vivid description, and you couldn't be happier to do exactly how he imagines it. You've been craving for more stimulation from hearing Sans' voice dripping with lust, so might as well give your body what it wants.

You dip your middle finger into the slick entrance, only testing it to make sure you're ready, before thrusting in much deeper and much faster, just like how Sans would do it. With a strangled moan, you pump your fingers in time with the noises you're hearing from the other end. "Saaaans...! I-I'm gonna cum if I keep this up...!"

["G-Go for it, kiddo...! It's not gonna take much longer for me anyway, nnnh! Haven't cum in days, after all..."] Sans moans back, his pants getting heavier and faster. You can tell that he's desperately trying to not to get too loud, his brother being in the room next to his and all. The slick noises that you can only assume to be his pre-cum dribbling all over his skeletal hand as he furiously strokes his member, combined with his voice only adds more fire to your quickly approaching climax.

"Aah, S-Sans, Sans...! I'm gonna cum, oh god, I-I want you so bad!" your whimpers getting louder by the second. "I-I'm...!"

["That's—nnnngh—that's it, c'mon... I'm almost there too! Scream my name, k-kiddo...!"]

And scream you do. Your fingers slips in past the second knuckle to its hilt, grazing along sensitive areas and toppling you over into a powerful orgasm. Your toes curl in as your back arches off the bed, your other hand rubbing the sensitive clit while prolonging the peak, crying out Sans' name loud as you do so.

Even as you're riding out your orgasm, there's a muffled groan on the other end of the line. ["O-Ohhh fuuuuck... Nngh, that was good... CRAP!"]

The languid tone suddenly turns sharp. You wonder what's going on—dear lord, you pray to every deity in your head that Papyrus didn't just walk in on his brother having phone sex with you—but thankfully, your worries are uncalled for.

["Shit, shit, I totally forgot about grabbing tissue...! Pap's said he's gonna be doing laundry in the morning! There's no way I'm lettin' him wash this with his stuff...!"]

"Pfffft! L-Lemme guess! D-Did you just cum on your jacket or shirt?"

["Uuuugh, yeah... Damn, I'll have to hide this until next laundry day..."]

Considering the shuffling noises you hear, you can easily imagine Sans desperately rummaging about his room in search of somewhere to hide his sullied clothes. Sans must've heard your stiffled laugh since since he stops for a moment.

["H-Heh... Sorry for killing the mood."]

"It's okay, Sans... It was nice being able to spend some time with you, even if I'm not there."

["...Well, I should let you go. Better let you get some sleep."]

"Yeah..." you answer with a small yawn. "I'll be back soon, okay?"

["Of course. Oh and, kiddo...?"]

"Mm?"

["...Love you."]

Sans' gentle tone catches you a little off guard, but it also brings a wonderful warmth in your heart. Though you know that he can't see you, you give a warm smile and whisper back, "...Love you too, Sans."

With one last good night said to each other, you end the call and place the cell phone on the night stand next to the bed. The call went in a much different direction than you had expected, yet in the end, your homesickness and doubts have all been washed away.

Sure, there are still a few more days before you return to your hometown... however that doesn't matter anymore. Your determination to do the best you can for the sake of all monsters—especially your beloved Sans—has been renewed, and you feel as if nothing can stop you.

With one last happy sigh, you close your eyes and drift off to a peaceful slumber.


	19. Debauchery

**Summary for the Chapter:**

> Happy new years! I've been taking a break from writing mainly due to going on vacations and because I've been busy getting ready for the new year. I'm slowly getting myself back into writing, so here comes some random short ficlets based on some of the comments people have kindly left for me. Each ficlet will have the kink described on the side.

_-UF!Sans is in for a surprise (Bottom UF!Sans)_

When Sans from another timeline awoke and found that he was one again in bed with the human from the other timeline, he couldn't have been more ecstatic. He did enjoy the threesome last time he had been here with her and other him, but truth be told, it would've been much better if he had the human all for himself. And now that she was here alone with him, Sans threw off his jacket with the biggest grin on his face.

What he wasn't prepared for, was for this.

"Seriously, other Sans? Did you really think I was just going to let you have your way with me? Mm... Oh wow, you're tight...! Has other me not done this with you yet...!?"

All red Sans could do was whimper and moan as he tried to figure out how he ended up on his chest, his ass in the air while he was getting the lights fucked out of him from behind. His hands were bound down by what looked like two, blue phantasmal hands and what felt a little too much like a ghostly dick was plowing him with no mercy. He felt the human still for a moment to drape herself over his back and bite his trembling clavicle, causing him to cry out again.

None of this made sense. He should've been the one dominating her. He should be the one making her cry out his name. But none of that mattered anymore as the human continued to whisper things into his ear—such dirty things—and he broke down.

With one last whine, he cried out, "O-Oh god, p-please for the love of god j-just fuck me! I-I-I need your dick r-ramming into me! P-Please fill me with y-your cum a-and... and...!"

Sans didn't even have to imagine the grin that must've been on the human's face as she chuckled.

"Well, since you've asked so nicely... Nnh, I'm going to _destroy_ you, other Sans."

And he couldn't have been happier when she did.

 

 

_-Mirrors are fun (Sans decides to bring a giant mirror)_

When Sans said that he wanted to get a better look at you when he was fucking you, you imagined that it was going to be something embarrassing, sure, but this was far beyond what you thought he meant. After enough foreplay to get you dripping wet, Sans had hoisted you up on his lap while your back was to his chest, his towering cock ready to penetrate your entrance twitching in anticipation. What you weren't ready for was him to use his magic to bring over the large mirror sitting across the room, setting it only a mere foot from the both of you.

"U-Um... Sans...?"

"Shh, just watch."

With that, he slowly began pushing his thick member into you, keeping the pace painfully slow so that you could feel and see your tight lips spread wide to accommodate his girth.

You felt your face light up at the sight as Sans intentionally moved his hips so that you could get the best view of him languidly fucking you. Each thrust was accompanied with a small whine, your pants getting more shallow by the second from seeing every inch of Sans' phantasmal cock being massaged by your tight walls. The embarrassing sight and Sans' pace only drove you more wild, and when you do cry out your first peak, Sans kept his hand on your jaw to make sure that your eyes were glued on the mirror.

 

 

_-Tentacles are fun (Sans makes tentacle dicks)_

Sans had mentioned it from time to time that because his dick was made with magic, he had free reign over what kind of shape it took. You had first hand experience with this, such as the time he expanded it to close to twice its original size that it had pushed itself past your cervix, or the time he had been in heat and created two phantasmal cocks to burn through the heat faster. So when you had asked Sans what else he could do with it, the giant grin on his face should've been an indicator of what it would entail.

You whimpered and bit into the pillow as one writhing member—a tentacle shaped member, for that matter—filled your vagina, pushing against every inch of your inner walls that seemed impossible by human standards, and another equally squirming one was pushed into your other orifice. It felt as if you were about to burst from within, but Sans was good at controlling his magic. When the sensation was becoming too much, he eased off, ceasing the writhing of the two tentacles or decreasing their sizes so that you could have a breather. 

"Saaaaans..." you whined, pushing your hips towards his. "C-C'mon... I can take, nnh, I-I can take more."

"Oh? You sure, kiddo? Can you really handle it...?" you heard Sans growl in your ear, sending another shiver down your spine. "Well, how 'bout this one for you?"

Another sharp moan escaped your lips as you felt another smaller tentacle slither forward and flick at your sensitive clit. "Aaah! S-Sans, h-how many of those can you make—mmph!" Your voice was cut off as you saw a flash of blue and another, thick tentacle was thrust into your mouth.

"I can make as many as you want... Ahh, yeah, I like it when you lick it like that...!"

Quickly your mind became muddled into a lust filled haze again as Sans began moving all of the tentacles at once. Eyes lulling back at the immense pleasure bombarding you from within and from without, you leave a mental note somewhere in your mind that you'll need to ask Sans to do this more often.

 

 

_-Things get out of hand (Exhibitionism)_

Along with exceptionally bad puns, it seemed that Sans enjoyed pulling pranks from time to time. The whoopie cushion in the hand trick that he pulled on you when you first met underground many months ago had been one example. (Could the adding incidental music in Papyrus' life count as well?) you wondered time and time again. However, ever since you two officially started dating, Sans would try and pull off more daring pranks.

It started innocent enough. A quick hug here, a sneaked kiss there, a playful smack on the butt when you passed by him in town... That sort of thing. But considering Sans' personality, it didn't end there.

You weren't sure how Sans pulled it off. By "it", you mean how he managed to sneak his magic into your panties to create a thinner than usual member on it. Had it not been for the pure shock of it suddenly materializing and plunging into you, you would've surely cried out lewdly in the middle of the supermarket. You had fallen to your knees at the sudden rush of pleasure coursing through your body, and on the contrary, Sans had feigned ignorance and rushed to your side in concern. You still caught the hint of a smirk on his face, along with the tint of blue in his left eye, proving that he was behind this. 

No amount of glaring or whispered chastising words helped. Sans continued to help you get groceries while feigning the role of concerned boyfriend when he was the one causing the member inside you to writhe. At one point, the pleasure became too strong for you to fight off and you collapsed in Sans' arms, vision tearing from need as you pleadingly looked up at him.

Within an instant, you were swept up bridal style and in the next instant, he and you were in a small, dark room that seemed to be some kind of closet. Sans had used a shortcut to the backroom of the supermarket. After a heated whisper into your ear to keep quiet, everything became a blur.

Your jeans were yanked down along with the panties with the phantasmal member on it, and in one swift movement, your body was lifted up and pressed against the wall as Sans sheathed himself inside you. Stars flashed across your vision at the wonderful sensation of being filled to the brim, making you want to cry out. Still, the sounds you could hear from outside the closet reminded you of your current situation and you quickly bit into Sans' jacket to keep yourself quiet.

The coupling was fast paced—neither you nor Sans had a wish to be caught, after all. Sans' heavy breathing at your ear in addition to the frantic movement of his hips as he mercilessly pounded into you compounded your pleasure. Thus, it wasn't long before you reached your peak, followed closely by Sans cumming deep within you.

It's not even a few minutes afterwards that the short skeleton pulled himself out from you and slipped your panties and jeans back on... all the while leaving his seed in you. He gave you another teasing smirk before you realized that you were both standing in the unchecked areas of the supermarket again. Sans took your hand and nonchalantly continued on with the shopping, obviously enjoying your brightly flushed face from feeling the sticky cum slowly seeping out of you.

Oh, you were going to get him back for this some day! You weren't sure how, but you were definitely going to make him pay for this prank sooner or later.


End file.
